Question

You flip a fair coin four times. “Heads” is called a success. The possible outcomes are shown in this tree diagram. What is the probability of the coin landing heads up exactly twice out of the four flips?

Picture of tree diagram is below

Answer 1

For the favourable case we need to count the ways to get 2 heads and 2 tails. The count of permutations of two pairs of symbols is: 4!

Explanation: