SOLUTION: If three coins are tossed, what is the probability that I will get two heads and a tail? We just recently started probability and the whole "at least two heads" i really throwin

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Question 997484: If three coins are tossed, what is the probability that I will get two heads and a tail?
We just recently started probability and the whole "at least two heads" i really throwing me off.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the probability you will get 2 heads and a tail is 3 out of 8 = 3/8 = .375

let's look at the total possibilities.

you can get:

H H H
H H T
H T H
T H H
H T T
T H T
T T H
T T T

out of these possibilities, 3 of them contain EXACTLY two heads and 1 tail.
those are:

H H H
H H T *****
H T H *****
T H H *****
H T T
T H T
T T H
T T T

the probability that you will get EXACTLY 2 heads and a tail is therefore 3/8 = .375.

out of these possibilities, 4 of them contain AT LEAST 2 heads.
those are:

H H H *****
H H T *****
H T H *****
T H H *****
H T T
T H T
T T H
T T T

that probability is the sum of getting EXACTLY 2 heads and a tail, plus the probability of getting EXACTLY 3 heads.

that probability is therefore equal to 3/8 + 1/8 = 4/8 = 1/2. = .5