If a fair coin is flipped eight times in a row, what is the probability that there will be at least one head and one tail?  Choose the correct choice from the following answers
A) 3/4	B) 11/12	C) 31/32	D) 127/128	E) 255/256
The number of possible outcomes is 2^8 = 256   There is one way to get no heads and one way to get no tails.   Thus there are 254 outcomes with at least one head and one tail.   P(at least one head and one tail) = 254/256 = 127/128   The answer is 127/128.
<result>D</result>
If a fair coin is flipped eight times in a row, what is the probability that there will be at least one head and one tail?