A trick coin has been weighted so that heads occurs with a probability of p = 2/3,

Question:

A trick coin has been weighted so that heads occurs with a probability of p = 2/3, and p(tails) = 1/3. If you toss this coin 72 times,
a. How many heads would you expect to get on average?
b. What is the probability of getting more than 50 heads?
c. What is the probability of getting exactly 50 heads?