If a fair coin is flipped seven times in a row, what is the probability that there will be at least one head and one tail?
Select the correct option.
A) 3/4	B) 11/12	C) 15/16	D) 31/32	E) 63/64
The number of possible outcomes is 2^7 = 128   There is one way to get no heads and one way to get no tails.   Thus there are 126 outcomes with at least one head and one tail.   P(at least one head and one tail) = 126/128 = 63/64   The answer is 63/64.
<result>E</result>
If a fair coin is flipped seven times in a row, what is the probability that there will be at least one head and one tail?