Pamela buys a windbreaker, a shirt, a jumpsuit and a skirt. The average cost of these items is $35. The total cost of the jumpsuit and the skirt is ²₅ of the total cost of the windbreaker and the shirt. If the windbreaker costs $13.70 and the skirt costs $6.50, find the difference in cost between the shirt and the jumpsuit.
Total cost of the 4 items
= 4 x 35
= $140

Total cost of the jumpsuit and the skirt = 2 u
Total cost of the windbreaker and the shirt = 5 u

Total cost of the 4 items
= 2 u + 5 u
= 7 u

7 u = 140

1 u = 140 ÷ 7 = 20

Total cost of the jumpsuit and the skirt
= 2 u
= 2 x 20
= $40

Cost of the jumpsuit
= 40 - 6.50
= $33.50

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

Cost of the shirt
= 100 - 13.70
= $86.30

Difference in cost between the shirt and the jumpsuit
= 86.30 - 33.50
= $52.80

Answer(s): $52.80