Question

a jar contains $3.60 in nickels and quarters. there are 28 coins in all. how many of each coin is in the jar?

Answer 1

Answer is 17 nickels and 11 quarters

Step by step

We know the following

.05n + .25q = 3.60

n = 28 - q

Substitute the 2nd equation value for n in the first equation

.05(28-q) + .25q = 3.60
Distribute

1.4 - .05q + .25q = 3.60

Subtract 1.4 from both sides to isolate variables

1.4 - 1.4 -.05q + .25q = 3.60 - 1.4
Simplify

.20q = 2.20
Divide both sides by .20

.20/.20q = 2.20/ .20

q = 11

So we have 11 quarters

We use the 2nd equation to find buckles

n = 28 - q

n = 28 - 11

n = 17

17 nickels and 11 quarters

Check your work

17(.05) + 11(.25) = 3.60

.85 + 2.75 = 3.60

3.60 = 3.60

Solution equals and is true
Problem solved