I'm lost on how to answer these questions. I just don't know where to start. Please help!

The probability of a french hen truly having citizenship is .81, find the probability that exactly 2 hens out of three have citizenship.

and

If there is an infinite number of calling birds, and the probability of a bird actually calling is .63, find the probability of finding the first calling bird on the third attempt.

Please solve and then explain. Thanks!