Nicole buys a dress, a windbreaker, a skirt and a jacket. The average cost of these items is $35. The total cost of the skirt and the jacket is ³₄ of the total cost of the dress and the windbreaker. If the dress costs $14.90 and the jacket costs $15.60, find the difference in cost between the windbreaker and the skirt.
Total cost of the 4 items
= 4 x 35
= $140

Total cost of the skirt and the jacket = 3 u
Total cost of the dress and the windbreaker = 4 u

Total cost of the 4 items
= 3 u + 4 u
= 7 u

7 u = 140

1 u = 140 ÷ 7 = 20

Total cost of the skirt and the jacket
= 3 u
= 3 x 20
= $60

Cost of the skirt
= 60 - 15.60
= $44.40

Total cost of the dress and the windbreaker
= 4 u
= 4 x 20
= $80

Cost of the windbreaker
= 80 - 14.90
= $65.10

Difference in cost between the windbreaker and the skirt
= 65.10 - 44.40
= $20.70

Answer(s): $20.70