Question

Elise took all of her cans and bottles from home to the recycling plant. The number of cans was one more than four times the number of bottles. She earned $0.10 for each can and $0.12 for each bottle, and ended up earning $2.18 in all. How many cans and bottles did she recycle?

Answer 1

0.10c + 0.12b = 2.18
c = 4b + 1

0.10(4b + 1) + 0.12b = 2.18
0.40b + 0.10 + 0.12b = 2.18
0.40b + 0.12b = 2.18 - 0.10
0.52b = 2.08
b = 2.08 / 0.52
b = 4 <==== she had 4 bottles

c = 4b + 1
c = 4(4) + 1
c = 16 + 1
c = 17 <=== she had 17 cans