12 different biology books and 8 different chemistry books lie on a shelf. In how many ways can a student pick 2 books of each type?  Choose the correct choice from the following choices:
A) 80	B) 160	C) 720	D) 1600	E) 1848

Rationale: no . of ways of picking 2 biology books ( from 12 books ) = 12 c 2 = ( 12 * 11 ) / 2 = 66 no . of ways of picking 2 chemistry books ( from 8 books ) = 8 c 2 = ( 8 * 7 ) / 2 = 28 total ways of picking 2 books of each type = 66 * 28 = 1848 ( option e )
Answer: E