10 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?
Select the correct option.
A) 80	B) 160	C) 720	D) 1100	E) 1260

Rationale: "no . of ways of picking 2 biology books ( from 10 books ) = 10 c 2 = ( 10 * 9 ) / 2 = 45 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 = 45 * 28 = 1260 ( option e )"
Answer: E