Question

I have some five-rupee coins and some two-rupee coins. The number of two rupee coins is twice the number of five rupee coins. the total money I have is 108 rupees. So how many five-rupee coins and how many two- rupee coins do I have ?

Answer 1

number of rs 5 coin=a
number of rs 2 coin=2a
cost of rs 5 coin=5a
cost of rs 2 coin =4a(2a x 2)
acoording to question,
5a+4a=108
9a=108
a=108/9
a=12
no. of rs 5 coin=12
no. of rs 2 coin=12 x 2=24

Answer 2

Given:

I have some five-rupee coins and some two-rupee coins. The number of two rupee coins is twice the number of five rupee coins. The total money I have is 108 rupees.

To Find:

So how many five-rupee coins and how many two-rupee coins do I have ?

Solution:

Let the number of Rs.5 coin = a

Let the number of Rs. 2 coin = 2a

So,

Cost of Rs.5 coin = 5a

Cost of Rs.2 coin = 4a (2a x 2)

Acoording to question,

5a + 4a = 108

9a = 108

a = 108/9

a = 12

Therefore,

Number of Rs.5 coin = a = 12

Number of Rs.5 coin = 2a = 12 x 2 = 24

Hence, I have 12 five-rupee coins and 24 two-rupee coins.