Question

Ivan has $8.75 in nickels and quarters in his desk drawer. The number of nickels is twice the number of quarters. How many coins of each type does he have?

Answer 1

• The number of nickels coins are : 50

• and the number of quarter coins are: 25

Explanation:

Let n denote the number of nickels.

and q denote the number of quarters.

1 nickel=0.05 dollar

and 1 quarter=0.25 dollar

Hence, we have:

0.05n+0.25q=8.75

( Since, Ivan has $8.75 in nickels and quarters in his desk drawer )

On multiplying both side of the equation by 100 we have:

5n+25q=875

on dividing both side of the equation by 5 we have:

n+5q=175-----------------(1)

Also, n=2q---------------(2)

( Since, the number of nickels is twice the number of quarters )

Hence, on putting equation (2) in equation (1) we have:

2q+5q=175

i.e.

7q=175

i.e. q=25

and on putting the value of q in equation (2) we have:

n=50

Answer 2

When Ivan divides his coins into groups of 2 nickels and 1 quarter, worth $0.35, he find that he has $8.75/$0.35 = 25 such groups.

Ivan has 25 quarters and 50 nickels.