The total cost of 8 vests and 8 jumpsuits was $472. Tina bought 10 such vests, 8 such jumpsuits and a cardigan for $568. If the total cost of a dress and a vest was $58, find the difference in cost between the vest and the dress.
Let 1 V be 1 vest.
Let 1 J be 1 jumpsuit.
Let 1 D be 1 dress.

8 V + 8 J = 472 --- (1)

1 V + 1 J = 472 ÷ 8
1 V + 1 J = 59 --- (2)

1 V + 1 D = 58 --- (3)

10 V + 8 J + 1 D = 568 --- (4)

(4) - (1)
(10 V + 8 J + 1 D) - (8 V + 8 J) = 568 - 472 
10 V - 8 V + 8 J - 8 J + 1 D = 96

2 V + 1 D = 96 --- (5)

(5) - (3)
(2 V + 1 D) - (1 V + 1 D) = 96 - 58
2 V - 1 V + 1 D - 1 D = 38
2 V - 1 V = 38

1 V = 38

From (3)
1 V + 1 D = 58
38 + 1 D = 58

1 D = 58 - 38 = 20

Difference in the cost between the vest and the dress
= 1 V - 1 D
= 38 - 20
= $18

Answer(s): $18