The total cost of 7 jumpsuits and 7 windbreakers was $385. Tina bought 9 such jumpsuits, 7 such windbreakers and a cardigan for $481. If the total cost of a blazer and a jumpsuit was $61, find the difference in cost between the jumpsuit and the blazer.
Let 1 J be 1 jumpsuit.
Let 1 W be 1 windbreaker.
Let 1 B be 1 blazer.

7 J + 7 W = 385 --- (1)

1 J + 1 W = 385 ÷ 7
1 J + 1 W = 55 --- (2)

1 J + 1 B = 61 --- (3)

9 J + 7 W + 1 B = 481 --- (4)

(4) - (1)
(9 J + 7 W + 1 B) - (7 J + 7 W) = 481 - 385 
9 J - 7 J + 7 W - 7 W + 1 B = 96

2 J + 1 B = 96 --- (5)

(5) - (3)
(2 J + 1 B) - (1 J + 1 B) = 96 - 61
2 J - 1 J + 1 B - 1 B = 35
2 J - 1 J = 35

1 J = 35

From (3)
1 J + 1 B = 61
35 + 1 B = 61

1 B = 61 - 35 = 26

Difference in the cost between the jumpsuit and the blazer
= 1 J - 1 B
= 35 - 26
= $9

Answer(s): $9