Julie buys a sweater, a jumpsuit, a blazer and a coat. The average cost of these items is $35. The total cost of the blazer and the coat is ²₅ of the total cost of the sweater and the jumpsuit. If the sweater costs $13.60 and the coat costs $8.50, find the difference in cost between the jumpsuit and the blazer.
Total cost of the 4 items
= 4 x 35
= $140

Total cost of the blazer and the coat = 2 u
Total cost of the sweater and the jumpsuit = 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 blazer and the coat
= 2 u
= 2 x 20
= $40

Cost of the blazer
= 40 - 8.50
= $31.50

Total cost of the sweater and the jumpsuit
= 5 u
= 5 x 20
= $100

Cost of the jumpsuit
= 100 - 13.60
= $86.40

Difference in cost between the jumpsuit and the blazer
= 86.40 - 31.50
= $54.90

Answer(s): $54.90