Question

What is the conditional probability that exactly four heads appear when a fair coin is flipped five times

Answer 1

5/32

Explanation:

If a coin if flipped five times with four heads, then it has exactly one tail. The number of way to arrange four heads and one tail are as follows:

T H H H H

H T H H H

H H T H H

H H H T H

H H H H T

Essentially, there are five way because there are five "positions" where the tail could be.

Then, you need to find the total amount of possibilities for flipping a coin five times. Every time you flip it, there are two possibilities- heads and tails. Therefore, for five flips, the total amount of possibilities is

2x2x2x2x2 = 32

You know that

probability= # of desired outcome

----------------------------------

# of total outcomes

So the probablity is 5/32.