From 6 biologists and 7 chemists a committee of 3 biologists and 3 chemists are to be formed. How many committee can be formed if no restrictions are imposed?
a) 20
b) 35
c) 700
d) 25,200
e) none of the choices.

Are you familiar with combinations? If you have a group of A objects (or people as in this case) you can select B of them in C(A,B) ways, where


C(A,B) = \frac {A!} {(A-B)! B!}


So for example for committee of 3 people from a pool of 8 can be selected is:


\frac { 8!} {5!3!} = \frac {8 \times 7 \times 6} {3 \times 2 \times 1 } = 56
ways.

So for your problem use combinations to figure out how many different ways the biologists can be selected and multiply by how many different ways the chemists can be selected.