Flynn buys a coat, a windbreaker and a vest. The average cost of these items is $89. The cost of the vest is four times the total cost of the coat and the windbreaker. If the coat costs $14, find the difference in cost between the windbreaker and the vest.
Total cost of the 3 items
= 3 x 89
= $267

Total cost of the coat and the windbreaker = 1 u
Cost of the vest = 4 u

Total cost of the 3 items 
= 1 u + 4 u
= 5 u

5 u = 267 

1 u = 267 ÷ 5 = 53.40

Total cost of the coat and the windbreaker = $53.40

Cost of the windbreaker 
= 53.40 - 14
= $39.40

Cost of the vest
= 4 u
= 4 x 53.40
= $213.60

Difference in cost between the windbreaker and the vest
= 213.60 - 39.40
= $174.20

Answer(s): $174.20