Julian had $294 and David had $100 at first. Each of them bought an identical sweater and an identical jumpsuit from the same shop. The jumpsuit cost 2 times as much as the sweater. In the end, Julian had 3 times as much money as David. What was the cost of the sweater?

	Julian	David	Difference
Before	$294	$100	$194
Change	- 1 sweater - 1 jumpsuit	- 1 sweater - 1 jumpsuit
After	3 u	1 u	2 u

Since Julian and David bought the same items, the difference  in their amounts remains the same.

Difference in the amounts that they had
= 3 u - 1 u
= 2 u

2 u = 294 - 100
2 u = 194

1 u = 194 ÷ 2 = 97

Amount that David had in the end
= 1 u
= $97

Cost of 1 sweater and 1 jumpsuit
= 100 - 1 u
= 100 - 97
= $3

The jumpsuit cost 2 times as much as the sweater.

Cost of 1 sweater = 1 p
Cost of 1 jumpsuit = 2 p

Total cost of 1 sweater and 1 jumpsuit
= 1 p + 2 p
= 3 p

3 p = 3

1 p = 3 ÷ 3 = 1

Cost of the sweater
= 1 p
= $1

Answer(s): $1