Question

Jack and beth are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of shiny wrapping paper. Jack sold 5 rolls of plain and 8 rolls of shiny for a total of $190. Beth sold of 5 rolls plain and 3 shiny for a total of $90. Find the cost of each roll of wrapping paper

Answer 1

Cost of a roll of plain wrapping paper = $6

Cost of a roll of shiny wrapping paper = $20

Explanation:

Let
`x` denotes cost of a roll of plain wrapping paper and
`y` denotes cost of roll of shiny wrapping paper.

Jack sold 5 rolls of plain and 8 rolls of shiny for a total of $190.

`5x+8y=190\,\,\,(i)`

Beth sold of 5 rolls plain and 3 shiny for a total of $90.

`5x+3y=90\,\,\,(ii)`

Subtract (ii) from (i).

`8y-3y=190-90\\5y=100\\y=20`

Put
`y=20` in (ii)

`5x+3(20)=90\\5x+60=90\\5x=90-60\\5x=30\\x=6`

Therefore,

Cost of a roll of plain wrapping paper = $6

Cost of a roll of shiny wrapping paper = $20