story problems

Question

A box of chalk and 2 staplers cost $10.  3 boxes of chalk and 2 staplers cost $18.  Find the total cost of 1 box of chalk and 1 stapler.

Answer 1

c=cost of chalk

s=cost of stapler

c+2s=$10

3c+2s=$18

subtract the first equation from the second

2c=$8

c=$4.00

$4+2s=$10

2s=$10-$4

2s=$6

s=$3.00

$4.00+$3.00=$7.00