# Math Help - Probability question

1. ## Probability question

The following was confusing me, so any help would be appreciated!

Suppose we throw a fair coin 3 times. Let X be the number of heads. Find the probability distribution function of X.

2. $P(X) = {{3}\choose {X}} \left( {.5} \right)^3 ,\quad X = 0,1,2,3$