Question

A vendor bought toffees at 6 for a rupee. Howout of 7 consonants and 4 vowels, how many words of 3 consonants and 2 vowels can be formed? Many for a rupee must he sell to gain 20%?

Answer 1

Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) = (7C3*4C2)

= 210.

Number of groups, each having 3 consonants and 2 vowels = 210.

Each group contains 5 letters.

Number of ways of arranging 5 letters among themselves = 5! = 120

Required number of ways = (210 x 120) = 25200.