Joe and Rob are selling wrapping paper for a school fundrais

Joe and Rob are selling wrapping paper for a school fundraiser. Customers can buy rolls of plain wrapping paper and rolls of holiday wrapping paper. Joe sold 2 rolls of plain wrapping paper and 8 rolls of holiday wrapping paper for a total of $88. Rob sold 10 rolls of plain wrapping paper and 9 rolls of holiday wrapping paper for a total of $161. What is the cost each of one roll of plain wrapping paper and one roll of holiday wrapping paper?

Solution

solution:

suppose the cost of one roll of plain wrapping paper is x and one roll of holiday wrapping paper is y

now

according to problem

2x+8y = 88

10x+9y=161

solving these two equations simultaneously

x=44-4y

put in equation 2

10(44-4y) + 9y =161

31y=279

y=9

and

x=44-4*9=8

hence cost of 1 plain paper= 8$

hence cost of 1 holiday paper= 9$