Question

A boy has 3 library tickets and 8 books of his interest in the library. Of these 8 books, he does not want to borrow Chemistry part II, unless Chemistry part I is also borrowed. In how many ways can he choose the three books to be borrowed?

Answer 1

Answer:

41

Step-by-step explanation:

Hi,

Given there are 8 books of a boy's interest in the library which

includes Chemistry part I and Chemistry Part II.

We can divide the selection scenario into following cases:

Case 1: Chemistry Part II is borrowed

Chemistry part II is borrowed suggests that he had also

borrowed Chemistry Part I so the 3rd book could be any one

from the remaining 6 books, hence number of ways this

combination could be chosen are 6

Case 2: Chemistry Part II is not borrowed

All the 3 books are to be chosen from any of the remaining 3

books which could be done in ⁷C₃ ways = 35 ways

Hence total number of ways can the boy choose to borrow 3

books are (6 + 35) = 41 ways.

Hope, it helps !