Question

There are 12 copies of Mathematics, 7 copies of Engineering, 3 different books on Medicine and 2 different books on Economics. Find the number of ways in which one or more than one book can be selected? ​

Answer 1

Total number of ways of selecting books = ways for selecting maths * ways of selecting engineering * ways of selecting Medicine *ways of selecting Economics.

Ways of selecting Maths = Not picking any+picking 1 maths +picking 2 maths+.....picking 12 maths = 1+1+1+...1 (13 times) =13.

Similarly ways of selecting engineering = 8

Ways of selecting Medicine= 23

Ways of selecting Economics = 22

Ways in which no book is selected is only one way i.e not selecting any book.

Hence total number of ways = (13*8*23*22)-1 = 3327