The total cost of 4 windbreakers and 4 blouses was $196. Tina bought 6 such windbreakers, 4 such blouses and a cardigan for $299. If the total cost of a shirt and a windbreaker was $67, find the difference in cost between the windbreaker and the shirt.
Let 1 W be 1 windbreaker.
Let 1 B be 1 blouse.
Let 1 S be 1 shirt.

4 W + 4 B = 196 --- (1)

1 W + 1 B = 196 ÷ 4
1 W + 1 B = 49 --- (2)

1 W + 1 S = 67 --- (3)

6 W + 4 B + 1 S = 299 --- (4)

(4) - (1)
(6 W + 4 B + 1 S) - (4 W + 4 B) = 299 - 196 
6 W - 4 W + 4 B - 4 B + 1 S = 103

2 W + 1 S = 103 --- (5)

(5) - (3)
(2 W + 1 S) - (1 W + 1 S) = 103 - 67
2 W - 1 W + 1 S - 1 S = 36
2 W - 1 W = 36

1 W = 36

From (3)
1 W + 1 S = 67
36 + 1 S = 67

1 S = 67 - 36 = 31

Difference in the cost between the windbreaker and the shirt
= 1 W - 1 S
= 36 - 31
= $5

Answer(s): $5