Barbara buys a skirt, a jumpsuit, a vest and a blazer. The average cost of these items is $33. The total cost of the vest and the blazer is ³₈ of the total cost of the skirt and the jumpsuit. If the skirt costs $15.70 and the blazer costs $13.20, find the difference in cost between the jumpsuit and the vest.
Total cost of the 4 items
= 4 x 33
= $132

Total cost of the vest and the blazer = 3 u
Total cost of the skirt and the jumpsuit = 8 u

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

11 u = 132

1 u = 132 ÷ 11 = 12

Total cost of the vest and the blazer
= 3 u
= 3 x 12
= $36

Cost of the vest
= 36 - 13.20
= $22.80

Total cost of the skirt and the jumpsuit
= 8 u
= 8 x 12
= $96

Cost of the jumpsuit
= 96 - 15.70
= $80.30

Difference in cost between the jumpsuit and the vest
= 80.30 - 22.80
= $57.50

Answer(s): $57.50