Xylia buys a vest, a windbreaker, a sweater and a dress. The average cost of these items is $34. The total cost of the sweater and the dress is ³₅ of the total cost of the vest and the windbreaker. If the vest costs $17.70 and the dress costs $17.60, find the difference in cost between the windbreaker and the sweater.
Total cost of the 4 items
= 4 x 34
= $136

Total cost of the sweater and the dress = 3 u
Total cost of the vest and the windbreaker = 5 u

Total cost of the 4 items
= 3 u + 5 u
= 8 u

8 u = 136

1 u = 136 ÷ 8 = 17

Total cost of the sweater and the dress
= 3 u
= 3 x 17
= $51

Cost of the sweater
= 51 - 17.60
= $33.40

Total cost of the vest and the windbreaker
= 5 u
= 5 x 17
= $85

Cost of the windbreaker
= 85 - 17.70
= $67.30

Difference in cost between the windbreaker and the sweater
= 67.30 - 33.40
= $33.90

Answer(s): $33.90