Urgent help regarding statistc

I wonder how to wirte the relevant formula and give the outcome to have some solution in the following mathematic questions:

A committee of 7 politicians is chosen from 10 liberal members,8 domocratic members and 5 independents.

1(a) In how many ways can this be done so as to include exactly 1 independent and at least 3 liberal members and at least 1 democratic member?

A survey is conducted to study customer behavior at a convenience store. It is found that 70 % of the customers patronize the convenience store everyday,56% of the customers purchase newspapers from the convenience store. For those customer who patronize the convenience store everyday, 75% of them purchase newspapers from the convenience store.

b) Calculate the probability that a randomly selected customer patronizes the convenience store everyday and purchase newspapers from the convenience store.

c) Given that a customer purchase newspapers from the convenience store,what is the probability that this customer patronizes the convenience store everyday?

d) Given that a customer does not patronize the convenience store everyday, what is the probability that this customer purchases newspapers from the convenience store?

****Please give me a hand to sort your answer and formula out here whenever you have thought through the ideas`!!Thanks~!!