Question

19. Tom has 30 coins with a value of $3.30. If they are all nickels and quarters, how many of each kind of coin does

he have?
Equation 1:
Equation 2:
Number of nickels:
Number of quarters:

Answer 1

n = nickels, q = quarters

Equation 1: n+q=30

Equation 2: 0.05n+0.25q = 3.30

Explanation:

From equation 1, n = 30-q

Substitute in Equation 2:

0.05(30-q) + 0.25q = 3.30

1.5 - 0.05q + 0.25q = 3.30

0.2q = 1.8

q = 9

Substitute in new equation:

n = 30-9

n = 21

It is important to note a nickel is worth 5 cents and a quarter is 25 cents. This helps us build the equations.