Tiffany buys a skirt, a shirt, a windbreaker and a blouse. The average cost of these items is $40. The total cost of the windbreaker and the blouse is ³₅ of the total cost of the skirt and the shirt. If the skirt costs $11.60 and the blouse costs $5.10, find the difference in cost between the shirt and the windbreaker.
Total cost of the 4 items
= 4 x 40
= $160

Total cost of the windbreaker and the blouse = 3 u
Total cost of the skirt and the shirt = 5 u

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

8 u = 160

1 u = 160 ÷ 8 = 20

Total cost of the windbreaker and the blouse
= 3 u
= 3 x 20
= $60

Cost of the windbreaker
= 60 - 5.10
= $54.90

Total cost of the skirt and the shirt
= 5 u
= 5 x 20
= $100

Cost of the shirt
= 100 - 11.60
= $88.40

Difference in cost between the shirt and the windbreaker
= 88.40 - 54.90
= $33.50

Answer(s): $33.50