Question

A collection of nicels and quarters is worth $3.60. There are 20 coins total. How many of each coin are in the collection?

Answer 1

n=nickels
q=quarters
n+q=20
0.05n+0.25q=3.60
5n+25q=360
n+5q=72
n+5(20-n)=72
n+100-5n=72
-4n=-28
n=7
7 nickels
13 quarters