You randomly text 20 of your friends to see who wants to go on a hiking trip. You think that they all respond to your requests independently of each other, and you estimate that each one is 7% likely to be available, interested in going hiking, and will actually text you back to accept the invitation.
a. Find the probability that at least 3 people would accept the invitation.
b. Find the expected number of people who would accept the invitation.
c. Find the variance of the number of people who would accept the invitation.