New to Binomial and Probability

Hi everyone,

Im new to all this. I have been spending alot of time these past few days doing various things related to Stats etc.

Im trying to understand, but its hard for me and I need help understanding. Here is a question;

Assume a binomial experiment in the following questions. Find the probability;

a) of exactly 5 successes, where n=7 and p=0.5

b) of between 8 and 12 successes, where n=15 and p=0.7

c) of at least 8 successes, where n=12 and p=0.5

Being so new I am having a hard time with this. Any help?

Duey