Question

Bansi has 3 times as many two-rupee coins as he has five-rupee coins. If he has in all a sum of Rs. 77, how many coins of each denomination does he have?

Answer 1

Let the number of five-rupee coins that Bansi has be x. Then the number of two-rupee coins he has is 3 times x or 3x.

The amount Bansi has:
(i) from 5 rupee coins, Rs. 5 × x = Rs. 5x.
(ii) from 2 rupee coins, Rs. 2 × 3x = Rs. 6x

Hence the total money he has = Rs. 11x

But this is given to be Rs. 77; therefore,

`11x = 77`

`x = 77/11 = 7`

Thus, number of five-rupee coins = x = 7. and 

number of two-rupee coins = 3x = 21.