Provide solution and choose the letter of the correct answer.

5. In how many ways can a committee of three consisting of two chemical engineers and one mechanical engineer can be formed from four chemical engineers and three mechanical engineers?

A.) 18 B.) 64 C.) 32 D.) None of these

6. In Mathematics examination, a student may select 7 problems from a set of 10 problems. In how many ways can he make his choice?

A.) 120 B.) 530 C.) 720 D.) 320