The total cost of 9 sweaters and 9 blouses was $567. Tina bought 11 such sweaters, 9 such blouses and a cardigan for $662. If the total cost of a jumpsuit and a sweater was $60, find the difference in cost between the sweater and the jumpsuit.
Let 1 S be 1 sweater.
Let 1 B be 1 blouse.
Let 1 J be 1 jumpsuit.

9 S + 9 B = 567 --- (1)

1 S + 1 B = 567 ÷ 9
1 S + 1 B = 63 --- (2)

1 S + 1 J = 60 --- (3)

11 S + 9 B + 1 J = 662 --- (4)

(4) - (1)
(11 S + 9 B + 1 J) - (9 S + 9 B) = 662 - 567 
11 S - 9 S + 9 B - 9 B + 1 J = 95

2 S + 1 J = 95 --- (5)

(5) - (3)
(2 S + 1 J) - (1 S + 1 J) = 95 - 60
2 S - 1 S + 1 J - 1 J = 35
2 S - 1 S = 35

1 S = 35

From (3)
1 S + 1 J = 60
35 + 1 J = 60

1 J = 60 - 35 = 25

Difference in the cost between the sweater and the jumpsuit
= 1 S - 1 J
= 35 - 25
= $10

Answer(s): $10