Vanessa buys a blouse, a skirt, a jacket and a vest. The average cost of these items is $25. The total cost of the jacket and the vest is ²₃ of the total cost of the blouse and the skirt. If the blouse costs $18.10 and the vest costs $12.70, find the difference in cost between the skirt and the jacket.
Total cost of the 4 items
= 4 x 25
= $100

Total cost of the jacket and the vest = 2 u
Total cost of the blouse and the skirt = 3 u

Total cost of the 4 items
= 2 u + 3 u
= 5 u

5 u = 100

1 u = 100 ÷ 5 = 20

Total cost of the jacket and the vest
= 2 u
= 2 x 20
= $40

Cost of the jacket
= 40 - 12.70
= $27.30

Total cost of the blouse and the skirt
= 3 u
= 3 x 20
= $60

Cost of the skirt
= 60 - 18.10
= $41.90

Difference in cost between the skirt and the jacket
= 41.90 - 27.30
= $14.60

Answer(s): $14.60