Wendy buys a jacket, a jumpsuit, a shirt and a vest. The average cost of these items is $40. The total cost of the shirt and the vest is ³₅ of the total cost of the jacket and the jumpsuit. If the jacket costs $15.10 and the vest costs $11.30, find the difference in cost between the jumpsuit and the shirt.
Total cost of the 4 items
= 4 x 40
= $160

Total cost of the shirt and the vest = 3 u
Total cost of the jacket and the jumpsuit = 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 shirt and the vest
= 3 u
= 3 x 20
= $60

Cost of the shirt
= 60 - 11.30
= $48.70

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

Cost of the jumpsuit
= 100 - 15.10
= $84.90

Difference in cost between the jumpsuit and the shirt
= 84.90 - 48.70
= $36.20

Answer(s): $36.20