Gabby buys a shirt, a dress, a jacket and a vest. The average cost of these items is $38. The total cost of the jacket and the vest is ³₅ of the total cost of the shirt and the dress. If the shirt costs $13.20 and the vest costs $18.50, find the difference in cost between the dress and the jacket.
Total cost of the 4 items
= 4 x 38
= $152

Total cost of the jacket and the vest = 3 u
Total cost of the shirt and the dress = 5 u

Total cost of the 4 items
= 3 u + 5 u
= 8 u

8 u = 152

1 u = 152 ÷ 8 = 19

Total cost of the jacket and the vest
= 3 u
= 3 x 19
= $57

Cost of the jacket
= 57 - 18.50
= $38.50

Total cost of the shirt and the dress
= 5 u
= 5 x 19
= $95

Cost of the dress
= 95 - 13.20
= $81.80

Difference in cost between the dress and the jacket
= 81.80 - 38.50
= $43.30

Answer(s): $43.30