The total cost of 7 vests and 7 jumpsuits was $406. Tina bought 9 such vests, 7 such jumpsuits and a cardigan for $488. If the total cost of a blouse and a vest was $52, find the difference in cost between the vest and the blouse.
Let 1 V be 1 vest.
Let 1 J be 1 jumpsuit.
Let 1 B be 1 blouse.

7 V + 7 J = 406 --- (1)

1 V + 1 J = 406 ÷ 7
1 V + 1 J = 58 --- (2)

1 V + 1 B = 52 --- (3)

9 V + 7 J + 1 B = 488 --- (4)

(4) - (1)
(9 V + 7 J + 1 B) - (7 V + 7 J) = 488 - 406 
9 V - 7 V + 7 J - 7 J + 1 B = 82

2 V + 1 B = 82 --- (5)

(5) - (3)
(2 V + 1 B) - (1 V + 1 B) = 82 - 52
2 V - 1 V + 1 B - 1 B = 30
2 V - 1 V = 30

1 V = 30

From (3)
1 V + 1 B = 52
30 + 1 B = 52

1 B = 52 - 30 = 22

Difference in the cost between the vest and the blouse
= 1 V - 1 B
= 30 - 22
= $8

Answer(s): $8