8 out 1
If the die is a regular octahedron, then the probability for each face is 1/8.
The probability to get heads once is 1/2 as the coin is fair The probability to get heads twice is 1/2x1/2 The probability to get heads three times is 1/2x1/2x1/2 The probability to get tails once is 1/2 The probability to get tails 5 times is (1/2)5 So the probability to get 3 heads when the coin is tossed 8 times is (1/2)3(1/2)5=(1/2)8 = 1/256 If you read carefully you'll understand that 3 heads and 5 tails has the same probability than any other outcome = 1/256 As the coin is fair, each side has the same probability to appear So the probability to get 3 heads and 5 tails is the same as getting for instance 8 heads or 8 tails or 1 tails and 7 heads, and so on
It is 4/8 = 1/2
The first thing to do is isolate how many ways there are to get 8 from two dice. These possibilities are:2,63,54,45,36,2so there are 5 possibilities. The probability of each of these combinations is (1/6)2 or 1/36, so the probability of getting 8 in one throw of 2 dice is 5/36For 9 throws, it is easier to calculate the probability of never getting 8. This is (1-probability of getting 8)9. (1-5/36)9 = (31/36)9 which is 0.26033. So the probability of getting an 8 somewhere along the line is 1-0.26033 or 0.7397
The probability of something NOT happening is the complement of the probability of something happening. Since the probability that you DO have 3 heads is 1/8 (that is, 1/2 cubed), the complement is 1 - 1/8 = 7/8.
The probability of an event happening can be at most 1: it cannot be 18.
8 out 1
If the die is a regular octahedron, then the probability for each face is 1/8.
The probability to get heads once is 1/2 as the coin is fair The probability to get heads twice is 1/2x1/2 The probability to get heads three times is 1/2x1/2x1/2 The probability to get tails once is 1/2 The probability to get tails 5 times is (1/2)5 So the probability to get 3 heads when the coin is tossed 8 times is (1/2)3(1/2)5=(1/2)8 = 1/256 If you read carefully you'll understand that 3 heads and 5 tails has the same probability than any other outcome = 1/256 As the coin is fair, each side has the same probability to appear So the probability to get 3 heads and 5 tails is the same as getting for instance 8 heads or 8 tails or 1 tails and 7 heads, and so on
The probability is 3/8.The probability is 3/8.The probability is 3/8.The probability is 3/8.
The probability is 8/20.
It is 1/52.
It is 4/8 = 1/2
The first thing to do is isolate how many ways there are to get 8 from two dice. These possibilities are:2,63,54,45,36,2so there are 5 possibilities. The probability of each of these combinations is (1/6)2 or 1/36, so the probability of getting 8 in one throw of 2 dice is 5/36For 9 throws, it is easier to calculate the probability of never getting 8. This is (1-probability of getting 8)9. (1-5/36)9 = (31/36)9 which is 0.26033. So the probability of getting an 8 somewhere along the line is 1-0.26033 or 0.7397
The easiest way of calculating this is to find the probability that all three are boys, as this is the only arrangement that does not fit the criteria. Then work out the answer by taking this away from 1. Probability that all three are boys = 1/2 x 1/2 x 1/2 = 1/8. probability of there being at least one girl is 1 - 1/8 = 7/8 or 87.5%
7/8