Gwen buys a jacket, a dress, a jumpsuit and a windbreaker. The average cost of these items is $22. The total cost of the jumpsuit and the windbreaker is ³₅ of the total cost of the jacket and the dress. If the jacket costs $12.80 and the windbreaker costs $17.50, find the difference in cost between the dress and the jumpsuit.
Total cost of the 4 items
= 4 x 22
= $88

Total cost of the jumpsuit and the windbreaker = 3 u
Total cost of the jacket and the dress = 5 u

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

8 u = 88

1 u = 88 ÷ 8 = 11

Total cost of the jumpsuit and the windbreaker
= 3 u
= 3 x 11
= $33

Cost of the jumpsuit
= 33 - 17.50
= $15.50

Total cost of the jacket and the dress
= 5 u
= 5 x 11
= $55

Cost of the dress
= 55 - 12.80
= $42.20

Difference in cost between the dress and the jumpsuit
= 42.20 - 15.50
= $26.70

Answer(s): $26.70