A nursery owner buys 7 panes of glass to fix some damage to his greenhouse. The 7 panes cost $15.05, Unfortunately, he breaks 2 panes while repairing the damage. What is the cost of another 2 panes of glass?

1 Answer
Feb 22, 2018

"Two panes of glass cost $4.30."

Explanation:

You can find this answer by using logic.

First find the cost of one pane of glass (the "unit cost")

7 panes of glass cost $15.05, so one pane of glass costs

15.05 -: 7

color(white)(nn) $2.15 larr cost of one pane of glass

Then use that answer to find the cost of two panes of glass

If one pane of glass costs $2.15, then 2 panes cost

2 xx $2.15

color(white)(.)$4.30 larr cost of two panes of glass

Answer:
"Two panes of glass cost $4.30."