Question

A sum of rs. 6.40 is made up of 80 coins which are either 10-paise or five-paise coins. How many are of 5-p.? Shortcut

Answer 1

Please see the attachment

Answer 2

Dear Student,

◆ Answer -

5 p coins = 32 coins

● Explanation -

Let x be no of 10 p coins and y be no of 5 p coins.

Condition 1 : total no of coins is 80 coins.

x + y = 80 ...(1)

Condition 2 : total sum is ₹ 6.40 = 640 p.

10x + 5y = 640

2x + y = 128 ...(2)

Substract (1) from (2),

(2x + y) - (x + y) = 128 - 80

x = 48 coins

Then to find y,

48 + y = 80

y = 80 - 48

y = 32 coins

Hence, there are 32 coins of 5 p.

Thanks dear. Hope this helps you...