Fanny buys a windbreaker, a skirt, a blazer and a vest. The average cost of these items is $55. The total cost of the blazer and the vest is ³₈ of the total cost of the windbreaker and the skirt. If the windbreaker costs $10.20 and the vest costs $10.70, find the difference in cost between the skirt and the blazer.
Total cost of the 4 items
= 4 x 55
= $220

Total cost of the blazer and the vest = 3 u
Total cost of the windbreaker and the skirt = 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 vest
= 3 u
= 3 x 20
= $60

Cost of the blazer
= 60 - 10.70
= $49.30

Total cost of the windbreaker and the skirt
= 8 u
= 8 x 20
= $160

Cost of the skirt
= 160 - 10.20
= $149.80

Difference in cost between the skirt and the blazer
= 149.80 - 49.30
= $100.50

Answer(s): $100.50