Answer to Question #13570 in Algebra for Ken

Question

What is the probability of obtaining exactly five heads in six flips of a coin, given that at least one is a head?

Answer 1

The probability that you will toss five heads in six coin tosses given that at least one is a head is the same as the probability of tossing four heads in five coin tosses.

There are 32 permutations of five coins. Five of them have four heads. This is a probability of 5 in 32, or 0.15625.