If the coin is tossed twice, find the probability distribution of number of tails. What is the probability of getting exactly 3 Heads in five consecutive flips. If X is a random variable giving the number of heads that arise, construcit a Sic showing the probability distribution of X. I recently became interested it the probability of certain outcomes. So 6 of the 16 possible equally likely sequences result in exactly 2 heads out of the 4 tosses. Find the probability that there will be at least 5 heads with exactly 5 of the?. Theoretical vs. Python gives us a great way to test scenarios to see how likely certain scenarios are, by allowing you to run certain scenarios millions and millions of times, and calculate the number or times in a certain outcome happens. The total number of possible outcomes is therefore 4 and the number of outcomes where the result is two heads is 1. After all, real life is rarely fair. A probability is determined from an experiment, which is any activity that has an observable outcome like tossing a coin and observing whether it lands heads up or tails up. 34 Probability and Counting Techniques If you recall that the classical probability of an event E ⊆ S is given by P(E) = n(E) n(S) where n(E) and n(S) denote the number of elements of E and S respectively. n(S) = Total number of ways of drawing 3 balls out of 15 = 15 C 3 Let E = Event of drawing 3 balls, all of them are yellow. Intuitive idea: P(A) is the typical fraction of times A would occur if an experiment were repeated very many times. It's just a betting pool, either way. An Easy GRE Probability Question A fair-sided coin (which means no casino hanky-panky with the coin not coming up heads or tails 50% of the time) is tossed three times. Therefore, the probability that three flips of a coin will produce exactly one head is 3/8 or 0. However, the probability of getting exactly one heads out of seven flips is different (and the solution is given). The occurrence of heads or tails on one coin does not affect the occurrence of heads or tails on the other two coins. On your first flip, it lands on heads. A fair coin is tossed 10 times. You can get good score only by practicing more and more. YES we all know that for any random 3 flips, each sequence has equal probability of 1/8 For greater than 3 flips it is no longer equal, but that doesn't seem to explain everything. The ﬁrst set of three heads is called a run. Probablity of getting sequence of K equal results while tossing coin N times [duplicate] a tail then 8 heads, or 8 heads and then a tail, for a probability of 3/512. A coin is tossed 4 times. What is the probability of getting exactly 6 heads? 7. Most coins have probabilities that are nearly equal to 1/2. Recall n(S)=20 so P(exactly 3 red)=1/20. For instance, if you toss a fair coin a single time, the outcome (heads or tails) is completely random and unpredictable. 4096 number of possible sequences of heads & tails. On your first flip, it lands on heads. So, how'd this Saturday go? They converted 3-of-4 fourth-down tries, didn't throw an interception and averaged better than two yards per carry in a dizzying 48-22 non-win against woeful USF. However, if you suspect that the coin may not be fair, you can toss the coin a large number of times and count the number of heads. Another type of probability that is usable for some types of problems where we do not actually need to perform an experiment is theoretical probability. What is the probability of getting at least 2 heads? Answer: 0. The probability of tossing 4 coins and getting two heads and two tails is 3/8 or 0. p 4 = Probability of success, given that you need 4 more heads from the current point. It would not be too unlikely to get 3 heads/1 tail. 7870 and the probability of getting three or more heads in a row or three or more tails in a row is 0. Coin is on heads 2. 5 of coming up heads. What is the probability of tossing a fair coin 10 times and getting 10 heads in a row? A fair coin is tossed 10 times. So, three tosses of a coin constitute a single experiment, rather than three experiments. Discuss the various arguments (see Answer 4 above) for the correct probability. Then we generate a 0 and a 1 each with probability 4 9 each round, instead of the 2 9 using von Neumann’s method. A person draws two socks at random out of a drawer containing 3 black socks and 4 red socks. We provide examples on Probability problem on Coin shortcut tricks here in this. The results can then be analysed statistically to decide whether the coin is "fair" or "probably not fair". (b) (d) P(exactly 2 heads) P(exactly 4 hea. Probablity of getting sequence of K equal results while tossing coin N times [duplicate] a tail then 8 heads, or 8 heads and then a tail, for a probability of 3/512. So we could say that the probability of getting exactly two heads is 6 times, six scenarios and-- Or there's a couple of ways. -As a procedure is repeated again and again, the relative frequency probability of an event tends to approach the actual probability. For example, it could be a single toss of a coin, or three tosses, or an inﬁnite sequence of tosses. Let X be the number of heads obtained. p 4 = Probability of success, given that you need 4 more heads from the current point. 5 because the probability of not getting a heads (getting a tails) is also 1 out of 2. What is the probability that at least 5 of the flips come up heads? Flipping coin: we set h = head and t = tail. A biased coin where P(heads) =3/5 is flipped 4 times. 87) Three coins are tossed together. What is the probability of obtaining exactly two heads in the five tosses? It is known, by prior knowledge, that the probability of a single success (probability of a head in one toss of a coin) is fifty percent. Coin toss probability calculator helps us find the probability of getting either heads or tails when a coin is tossed the given number of times. A biased coin is tossed ten times. All heads would occur 1/32 times or 0. The total number of outcomes is simply since we're tossing a coin 6 times and each toss has only two possible outcomes. Probability does not tell us exactly what will happen, it is just a guide Example: toss a coin 100 times, how many Heads will come up? Probability says that heads have a ½ chance, so we can expect 50 Heads. 2 3 by matching up the possible outcomes a bit more carefully. Tossing a Biased Coin Michael Mitzenmacher When we talk about a coin toss, we think of it as unbiased: with probability one-half it comes up heads, and with probability one-half it comes up tails. Probabilities can also be thought of in terms of relative frequencies. 2nd coin tossed probability of getting tails is 1 in 2. N=3: To get 3 heads, means that one gets only one tail. A card is selected at random from a deck of 52 cards. The total number of possible outcomes is therefore 4 and the number of outcomes where the result is two heads is 1. MATH1005 Quizzes You are here: A coin is tossed 6 times. Predict what will happen if you change the probability of heads to 0. Then use rule 1, the addition rule. , HHH, HHT, HTH, HTT, THH, THT, TTH, TTT Out of which there are 4 set which contain at least 2 Heads i. Answer to A coin is tossed four times, and the sequence of headsand tails is observed. The possible outcomes of an experiment are called sample space of the experiment. So, if I flip a coin 100 times, is the likeliness of it landing exactly 50 times on either side any greater than it landing all 100 times on the same side? Short, non-numerical answer: yes it is, because there's only two ways for it landing all 100 times on the same side: either it lands heads every single time, or it lands tails every single time. Knowing a little bit about the laws of probability, I quickly knew the fraction "2/6" for two dice and "3/6" for three dice was incorrect and spent a brief moment computing and then explaining the true percentages. The probability that the player will jump from zero consecutive heads to two consecutive heads in one toss is zero. Once in the "3 tails" section which is TTTH and once in the "4 tails" section, which is TTTT. 2) b) Use simulations to find an empirical probability for the probability of getting exactly 5 heads in 10 tosses of an unfair coin in which the probability of heads is 0. , HHH, HHT, HH, THH So the probability is 4/8 or 0. 5 for obtaining a head when a coin is tossed. Find probability that a four shows on exactly two of the dice. The probability of getting exactly x success in n trials, with the probability of success on a single trial being p is: P(X=x) = nCx * p^x * q^(n-x) Example: A coin is tossed 10 times. more than 3 tails. Answer : Option A Explanation : Total number of balls = 4 + 5 + 6 = 15 Let S be the sample space. What is the probability that the next flip will be tails? This can lead to some unsettling probabilities: 1. them have exactly two heads. For the second part of question, you are not bothered with the results of 2nd to 6th toss. There are three more runs in this sequence, namely the next four tails, the next head, and the next tail. So, we got 99 heads already, but it doesn't increase the chance of getting a tail next toss. What is the probability of getting at least 3 heads. A pair of dice are rolled. Betting that someone will live is equivalent to putting a price on their heads; betting against them living is equivalent to accepting the contract for a hit. So that is $2\times 2\times 2\times 2$ results in total. In a spinning wheel casino game you pay $5 and can win $1, $3, $5, $20 or lose your bet. Exactly 2 heads: 1st toss is 100% either head or tails. Word problems on coin toss probability: 1. Taking it step by step, dividing seed by 9999 produces a nonnegative real number between 0 and 1. For example, it could be a single toss of a coin, or three tosses, or an inﬁnite sequence of tosses. Even if a question doesn't invoke the coin toss, the way we approach a coin toss problem can carry over to other types of probability questions. Probability problem on Coin. The probability of getting two heads in tossing a fair coin twice is therefore 1/4. What is the probability of getting three heads in tossing a coin three times? It is (1/2)3 = 1/8 or 0. A probability is determined from an experiment, which is any activity that has an observable outcome like tossing a coin and observing whether it lands heads up or tails up. In a probability experiment, two events E and F are said to be mutually exclusive if they cannot both occur. You don't want much chance of scoring under 150. The number of possible outcomes of each coin flip is 2 (either heads or tails. Find the probability of getting a number greater than 4. We need to find the probability of getting at least 1 head. Coin flipping, coin tossing, or heads or tails is the practice of throwing a coin in the air and checking which side is showing when it lands, in order to choose between two alternatives, sometimes used to resolve a dispute between two parties. Our probability is just this over the total number of outcomes. P(tomorrow it will rain). The number of heads, k, given n tosses follows a binomial distribution, Bin(k; n, r), where r is the probability of getting heads in an individual toss. If there is an equal probability of Alice, Ben, Charlie or Danièle being the driver of Danièle's motorcycle, then the probability of Ben being the driver can be. Suppose we were to toss an unbiased coin 4 times in succession. Answer (1 of 1): First of all, the probability of getting both coins to be heads is 1/4. Does that mean if the coin is tossed twice, we will get one heads? ' and find homework help for other Math. the probability is 50 percent of 50 percent of 50 percent. You may wish to explain that these events are independent. You're referring to the amazing story of a teenage cricket player for the Magpies Kristy Perrin, who indeed called the coin toss incorrectly 35 times in a row. A probability of zero is a result which cannot ever occur: the probability of getting five heads in four flips is zero. This is the aptitude questions and answers with discussion section on "Probability" with explanation for various interview, competitive examination and entrance test. Three coins are tossed simultaneously What is the probability of getting : i) two heads ii) at most one head iii) atleast two heads iv ) at most two heads please solve the query soon Thank you - Math - Probability. Try the following: 1. Dealing with "At Least": In L 2, prepare the " at least" (1 - binomcdf) probabilities, using as parameters the number of trials, the probability of occurrence, and one less than the value in L 1. What is the probability that at least 5 of the flips come up heads? Flipping coin: we set h = head and t = tail. Does that mean if the coin is tossed twice, we will get one heads? ' and find homework help for other Math. 5 (chance. This means the chance is reset to 1 out of 2 each time the coin is tossed. Take, for example, a coin toss. them have exactly two heads. 2 An ordinary coin is to be tossed twice in the usual way. A coin is tossed four times. Each time the coin is tossed there is a 1 out of 2 or 50% chance of the coin landing on heads or tails. What is the probability of getting (a) exactly six heads, (b) exactly three tails, (c) no heads, (d) three or fewer heads, (e) six or more tails, and (f) at least Posted 2 years ago. There are three more runs in this sequence, namely the next four tails, the next head, and the next tail. So the probability is ----- b) What is the probability of obtaining tails on each of the first 3 tosses That only happens 2 times. Math 115 Exam 2 Answers 1. Note that we have listed all the ways a first die and second die add up to 5 when we look at their top faces. Find probability of getting a "1" two times. The probability is thus 1 4. asked by Keonn'a on October 14, 2018; math. ) Find the probability that a person will throw 4, 8, and 10 on the first, second, and third tosses of a pair of dice. The minimum number of times a fair coin needs to be tossed, so that the probability of getting at least two heads is at least 0. there fore it is 12. Answer : Option A Explanation : Total number of balls = 4 + 5 + 6 = 15 Let S be the sample space. , HHH, HHT, HH, THH So the probability is 4/8 or 0. All heads would occur 1/32 times or 0. Dealing with "At Least": In L 2, prepare the " at least" (1 - binomcdf) probabilities, using as parameters the number of trials, the probability of occurrence, and one less than the value in L 1. Game Theory (Part 9) John Baez. The probability of getting a white ball first is 30 50 (30 white balls out 50 total). 4 CHAPTER 1. Theoretical vs. If 4 coins are tossed, find the following probability: 2 heads. An easier way would be to do a normal approx. What is the probability that either Sara or Kaleb tossed exactly three heads? Express your. 5? Close to 0. for a coin toss there are two possible outcomes, Heads or Tails, so P(result of a coin toss is heads) = 1/2. 5 coins are tossed together. Probability says that heads have a ½ chance, so we can expect 50 Heads. There are five ways to roll a 6: (1,5)(2,4)(3,3)(4,2), and (5,1). GMAT Math: the Probability "At Least" Question By Mike MᶜGarry on December 19, 2012 , UPDATED ON April 20, 2019, in GMAT Math , GMAT Math Basics In the first post in this series, I spoke about the AND rule and the OR rule in probability. for landing heads or tails. What Probability is, and what it is not. Hexaware Numerical Ability Question Solution - if 6 coins are tossed simultaneously what is the probability of getting atleast four heads Latest Hexaware Aptitude Question SOLUTION: if 6 coins are tossed simultaneously what is the probability of getting atleast four heads. Word problems on coin toss probability: 1. A coin is tossed 4 times. For instance, if you toss a fair coin a single time, the outcome (heads or tails) is completely random and unpredictable. The possibilities are T-H-H, H-T-H, and H-H-T. ( ) 1 1 7! 7 63 4 7,3 2 2 3! 4! C ⋅ = = ⋅ ⋅ ⋅ ⋅ ⋅ ⋅5 4 3 2 1 3 2 1⋅ ⋅ ⋅ ⋅ ⋅ ⋅4 3 2 1 7 35 128 1 2 = 2. What is the probability that the next flip will be tails? This can lead to some unsettling probabilities: 1. Logic would suggest that: "if no matter what sequence you choose, there is always one of the other seven that will beat it". If you toss a coin a 20 times, your probability of getting a tails is very, very close to 100%. For the favourable case we need to count the ways to get $2$ heads and $2$ tails. (1 Mark) (Q. What is the probability of getting exactly 2 heads?. Likewise, the probability of tails on four tosses is the probability of tails raised to the fourth power. As a class, discuss what the following statement means: “If you toss a fair coin, the probability of heads is 0. i think exactly like that, but then i would realize if we do that, what are the odds of gettin 3heads and 2 tails in no order???? wouldnt be 100%????? cuz its only a two sided coin and odds of gettin heads or tails is equal. What is the probability of getting at least 3 heads when 5 coins are tossed at same time? For the experiment of tossing a single fair coin 3 times, what is the probability of getting exactly 2 heads,?. Bag B contains 3 red coins and 4 white coins. Hexaware Numerical Ability Question Solution - if 6 coins are tossed simultaneously what is the probability of getting atleast four heads Latest Hexaware Aptitude Question SOLUTION: if 6 coins are tossed simultaneously what is the probability of getting atleast four heads. Math 115 Exam 2 Answers 1. The probability of having a girl is 1/2. The exact probability of the coin landing heads exactly 2 times is? Where p is the probability, n is the total events and. When ways to perform tasks in series, we multiply. So to get 7 heads and then 7 tails in that order is: But in this problem we don't care about order. Probability of Exactly 5 Heads in 8 Coins Flip - Duration: 4:31. In this applet, you can set the true probability of heads for your virtual coin, then toss it any number of times. Betting that someone will live is equivalent to putting a price on their heads; betting against them living is equivalent to accepting the contract for a hit. getting the sequence in three flips. And the probability that the first die shows an odd number is 1/2, as is the probability that the second does. Let's return to the coin-tossing experiment. C) Three dice are tossed. We might want to know the probability of getting a Head and a 4. All heads would occur 1/32 times or 0. The probability of getting a white ball first is 30 50 (30 white balls out 50 total). When 3 coins are tossed randomly 250 times and it is found that three heads appeared 70 times, two heads appeared 55 times, one head appeared 75 times and no head appeared 50 times. So there's six different scenarios, and we know that there's a total of 16 equally likely scenarios. What is the probability of getting at least 2 heads? Answer: 0. When ways to perform tasks in series, we multiply. Probability question - if a fair coin is tossed 5 times what is probability of getting all heads? More questions If you toss 10 fair coins in the air, what is the probability that EXACTLY 5 will land on tails?. Probability of a statement S: P(S) denotes degree of belief that S is true. The probability that a head comes up on the second toss is 1/2 regardless of whether or not a head came up on the ﬁrst toss. A coin is tossed 5 times. A coin is tossed 10 times then the probability of getting exactly 6 heads is? options:- a)3/5b)105/512c)105/10… Get the answers you need, now!. E={(1,4),(2,3),(3,2),(4,1)}. Question: Suppose you have two unfair coins. For example, suppose we have three coins. for a coin toss there are two possible outcomes, Heads or Tails, so P(result of a coin toss is heads) = 1/2. It is a form of sortition which inherently has two possible outcomes. " What happens to the proportion of heads? 4. What is the probability to get another head in the 100th toss? Theoretically, because each toss is independent, it should be again 50%. A probability is determined from an experiment, which is any activity that has an observable outcome like tossing a coin and observing whether it lands heads up or tails up. What is the probability of heads on the first toss, tails onn the second toss, and heads on the third and fourth tosses?. n = 5 because there are 5 trials (5 total tosses) r = 3 because we want 3 heads (3 successes) p = 0. Does that mean if the coin is tossed twice, we will get one heads? ' and find homework help for other Math. To the nearest thousandth, find the probability of getting 4 heads. Probability of getting exactly 8 heads in tossing a coin 12 times is 495/4096. six tosses, there are 2^6=64 possible outcomes. a) Calculate the theoretical probability of getting exactly 5 heads in 10 tosses when the probability of a head is 0. Without replacing the marble, you pull another marble out of the bag. An easier way would be to do a normal approx. Find the probability that both heads and tails occurs. Since there are 4 possible outcomes with one head only, the probability is 4/16 = 1/4. Classes Class 1 - 3. To find the probability, you divide 6 by the total number of possible outcomes (16) and you would get 6/16 = 3/8. If a fair coin is tossed five times, what is the probability of tossing exactly three heads? You toss a coin 5 times. SOLUTION: We set it up by counting how many things are in the sample space, then count how many ways of getting the three heads. What is the probability that it lands heads exactly 500 times? Answer: The previous way of solving this problem, just by counting, was as follows: Let n(E) be the number of ways that the coin can land exactly 500 times. If the coin is tossed 7 times, there are 2^7 = 128 possible outcome, and just one of them is all heads. When tossing a coin, the average. 3rd coin tossed probability of getting tails is 1 in 2. Suppose we were to toss an unbiased coin 4 times in succession. Probability is Just a Guide. For example, suppose we have three coins. With a "fair" coin, the probability of getting heads on a "single" flip at any time is 1/2. We saw earlier that P(exactly 2 red) =9/20. A) A coin is tossed 20 times. Coin A is tossed three times and coin B is tossed two times. So the probability is ----- c) What is the probability of obtaining four heads. An Introduction to Tree Diagrams. Similarly, the probability of observing four heads on four coin flips is 1/2*1/2*1/2*1/2 = 1/16. Given that it is rainy, there will be heavy traffic with probability $\frac{1}{2}$, and given that it is not rainy, there will be heavy traffic with probability $\frac{1}{4}$. Thus the probability of exactly 2 heads is 6/16 = 3/8. But it's a completely identical outcome for us, because they're really just heads. If a coin is flipped 3 times, what is the probability that it lands on heads at least once? While you could solve this problem by using the laws of independent events, this question can also illustrate the concept of the complement of an event. Therefore, the probability of throwing exactly two heads in three tosses of the coin is 3 out of 8, or or the decimal equivalent of which is 0. Users may refer the below detailed solved example with step by step calculation to learn how to find what is the probability of getting exactly 4 heads, if a coin is tossed ten times or 10 coins tossed together. a) Calculate the theoretical probability of getting exactly 5 heads in 10 tosses when the probability of a head is 0. Let X be the number of heads obtained. The probability is 1/6. getting the sequence in three flips. Since there are 4 possible outcomes with one head only, the probability is 4/16 = 1/4. In my town, it's rainy one third of the days. Probability does not tell us exactly what will happen, it is just a guide Example: toss a coin 100 times, how many Heads will come up? Probability says that heads have a ½ chance, so we can expect 50 Heads. Find probability of getting at least 14 heads. The probability that a head comes up on the second toss is 1/2 regardless of whether or not a head came up on the ﬁrst toss. Note: Including the words "single time" and "after" confuse this problem somewhat. Adding 1 makes it one of the three 1, 2, or 3. The count of permutations of two pairs of symbols is: $\frac{4!}{2!2!}=6$. There are4 Possible Outcomes with Two Coins Tossing that is is TT,TH,HT,HH,which means one possibility is having zero heads Therefore the Probaility of this is1/4 that is25%. What is the probability of getting no any two heads on consecutive tosses?. A probability of one represents certainty: if you flip a coin, the probability you'll get heads or tails is one (assuming it can't land on the rim, fall into a black hole, or some such). Practice Problems - Set Two. Worked-out problems on probability involving tossing or throwing or flipping three coins: 1. The probability of getting a white ball first is 30 50 (30 white balls out 50 total). The ﬁrst set of three heads is called a run. They can, however, tell you in advance what would be an upset — much like probability theory can tell you that getting three heads in a row in a coin toss is unlikely but is of no help in. Therefore, the probability that three flips of a coin will produce exactly one head is 3/8 or 0. Another type of probability that is usable for some types of problems where we do not actually need to perform an experiment is theoretical probability. The coin is flipped 10 times and the result of each flip is noted. Coin Toss Probability What is the probability of the Patriots winning 19 out of 25 coin tosses. To the nearest thousandth, find the probability of getting 4 heads. For pulling a black ball again, we have 19 black balls and 48 balls total, so the probability is 19 48. ( ) 1 1 7! 7 63 4 7,3 2 2 3! 4! C ⋅ = = ⋅ ⋅ ⋅ ⋅ ⋅ ⋅5 4 3 2 1 3 2 1⋅ ⋅ ⋅ ⋅ ⋅ ⋅4 3 2 1 7 35 128 1 2 = 2. The probability is thus 1 4. If a fair coin is tossed five times, what is the probability of tossing exactly three heads? You toss a coin 5 times. Thus, we get 1/2. A pair of dice are rolled. Probability says that heads have a ½ chance, so we can expect 50 Heads. 4) A coin is tossed four times and the sequence of heads and tails is observed. (d) A family has five children. A fair coin is tossed 5 times in a row. What is the probability of heads on the first toss, tails onn the second toss, and heads on the third and fourth tosses?. A coin is tossed 4 times. e head or tail. Discuss the various arguments (see Answer 4 above) for the correct probability. Note: Including the words "single time" and "after" confuse this problem somewhat. It doesn't always occur, but that is our expectation. The probability of an event is determined by dividing the number of successes by the total number of outcomes in the sample space. For the experiment of tossing a single fair coin 3 times, what is the probability of getting exactly 2 heads,? What is the probability of tossing a coin 5 times and getting 2 tails and 3 heads in that order?. The probability that a head comes up on the second toss is 1/2 regardless of whether or not a head came up on the ﬁrst toss. However, no coin is exactly symmetrical nor, in all likelihood, has a probability of landing heads of exactly 1 2. There are 2 red balls and 4 white balls in a box. Activity 1: Expected Values. What is the probability of exactly 2 heads occurring in the 6 tosses. What is the probability that (a) At least one of the dice shows an even number? P(at least one is even) = 1 - P(both are odd). Probability does not tell us exactly what will happen, it is just a guide. Find the probability of getting exactly three heads?. Coin Toss Probability What is the probability of the Patriots winning 19 out of 25 coin tosses. You can see that this is true because there are four different possibilities (TT, TH, HT, and HH) and only one of them yields two heads, HH. We may not see it. Of the eight possible outcomes, three have exactly one head. FIN3303 - Chap 10 Risk and Capital Budgeting: 100% Correct and Explained Chapter 10—Risk and Capital Budgeting MULTIPLE CHOICE 1. There are three more runs in this sequence, namely the next four tails, the next head, and the next tail. Each should occur half the time. Answer (1 of 1): First of all, the probability of getting both coins to be heads is 1/4. Hello experts, I need to calculate the probability of getting either 5 consecutive heads or 5 tails when tossing a coin 25 times. What is the probability that exactly two heads are tossed given that The first outcome was a head. Find probability that a four shows on exactly two of the dice. Over a large number of tosses, though, the percentage of heads and tails will come to approximate the true probability of each outcome. Report Abuse. An easier way would be to do a normal approx. Let n(S) be the total number of ways that the coin can land in 1000 tosses. Note that whereas the probability of tossing both heads and tails (in any order) is 50% or 1/2, and the probability of tossing two heads in a row is 25% or 1/4. Once in the "3 tails" section which is TTTH and once in the "4 tails" section, which is TTTT. Worked-out problems on probability involving tossing or throwing or flipping three coins: 1. find any outcome that has exactly two H's. A fair coin is flipped 9 times. Probability, p, is a number such that 0 ≤p≤1 , or 0% ≤p≤100%.