Question

Soham has a total of 11.25 rupees. He has 20-paise and 25-paise coins in a bag. He has total 50 coins in his bag. Find the number of 20-paise coins he has.

Answer 1

Let the number of 20 paise coins be x and no. of 25 paise coins be y.

ATQ

x+y=50 --------------------(1) and

20x+25y=1125 [∵, Rs. 11.25=1125 paise]

or, 4x+5y=225 -----------(2)

Multiplying (1) with 4 we get,

4x+4y=200 ---------------(3)

Subtracting (3) from (2) we get,

y=25

Putting in (1)

x=50-y=50-25=25

∴ x=25, y=25