Permutations & Combinations

(1) A Maths paper consists of section A and B.There are 8 questions in section A and 7
questions in section B.Candidates need to answer a total of 12 Questions in the paper.
Find the no. of ways to select the 12 questions if
a) there is no restrictions
b) he is required to answer all the questions in section A
c) he is required to answer at least 6 questions in section A.
(2) At a party,8 boys and 4 girls are going to take a group photogragh.In how many ways
can they be arranged ifa) all stand in a row
i) without any restrictions
ii) with only two girls stand next to each other.b) all the girls stand in the front row and all the boys stand in the back row?c) they are arranged in two rows of 6
i) with no restrictions?
ii) with all the girls standing next to each other?