Question

You buy 5 packs of batteries and 5 light bulbs for $60. The next day, you buy 4 packs of batteries and 3 light bulbs for $40.75. How much does each cost?

Answer 1

batteries: 4.75 light bulbs: 7.25

Explanation:

Lets say batteries are b and light bulbs are l.

So we have these:

5b+5l=60

4b+3l=40.75

Using the first one:

Divide by 5: b+l=12

Subtract b: l=12-b

Plug that in to get: 4b+3(12-b)=40.75

4b+36-3b=40.75 so b=4.75

This means b=4.75 and l=7.25