A study was made of frequent fliers, and it was found that 53% had an income over

Question:

A study was made of frequent fliers, and it was found that 53% had an income over $65,000 a year.
a. Fifteen frequent fliers were selected at random, and their incomes recorded. What is the probability that at least 10 had an income over $65,000 a year?
b. A further group of 12 fliers was selected at random. What is the probability that exactly eight had an income over $65,000 a year?