Question

Manju has ₹90 in her piggy bank in Re 1 coins and 50 paise coins. If the number of Re 1 coins is twice that of 50 paise coins, how many coins of each are there?

Answer 1

let the number of 50 paise coins be = x

given number of 1 rupee coin is twice that of 50 paise coin

so the number of 1 rupee = 2 * x = 2x

given total amount as 90 rupees

we know 50 paise = half of one rupee

50 paise = 1/2 rupee

2x * 1 rupee + x * 1/2 rupee = 90 rupee

2x + x/2 = 90 (taking LCM)

4x + x = 180

5x = 180

x = 180 / 5 = 36

so number of 50 paise coins = 36

and number of 1 rupee coins = 36 * 2 = 72