Question

If Marcos had 15 coins in nickels and quarters. He has three more quarters than nickels. Write a system of equations and solve to find the number of nickels and the number of quarters Marcos has.

Answer 1

Marcos has 6 nickels and 9 quarters

Solution:

Let "n" be the number of nickels

Let "q" be the number of quarters

Marcos had 15 coins in nickels and quarters

Therefore, we can say,

number of nickels + number of quarters = 15

n + q = 15 -------- eqn 1

He has three more quarters than nickels

Number of quarters = 3 + number of nickels

q = 3 + n -------- eqn 2

Eqn 1 and eqn 2 represents the system of equations

Substitute eqn 2 in eqn 1

n + 3 + n = 15

2n + 3 = 15

2n = 15 - 3

2n = 12

n = 6

Substitute n = 6 in eqn 2

q = 3 + 6

q = 9

Thus Marcos has 6 nickels and 9 quarters