Barbara buys a jumpsuit, a sweater, a blazer and a coat. The average cost of these items is $55. The total cost of the blazer and the coat is ³₈ of the total cost of the jumpsuit and the sweater. If the jumpsuit costs $16.50 and the coat costs $9.90, find the difference in cost between the sweater and the blazer.
Total cost of the 4 items
= 4 x 55
= $220

Total cost of the blazer and the coat = 3 u
Total cost of the jumpsuit and the sweater = 8 u

Total cost of the 4 items
= 3 u + 8 u
= 11 u

11 u = 220

1 u = 220 ÷ 11 = 20

Total cost of the blazer and the coat
= 3 u
= 3 x 20
= $60

Cost of the blazer
= 60 - 9.90
= $50.10

Total cost of the jumpsuit and the sweater
= 8 u
= 8 x 20
= $160

Cost of the sweater
= 160 - 16.50
= $143.50

Difference in cost between the sweater and the blazer
= 143.50 - 50.10
= $93.40

Answer(s): $93.40