At first, Ahmad, Charlie and Jack had the same amount of money. After Jack spent some of his money, Ahmad spent ²₇ of his money and Charlie spent ¹₂ of his money, Ahmad had $48 more than Charlie. In the end, the total amount of money the three boys had left was $331. How much money did Jack spend?

	Ahmad	Charlie	Jack	Total
Before	7x2 =  14 u	2x7 = 14 u	14 u
Change	- 2x2 = - 4 u	- 1x7 = - 7 u	- ?
After	5x2 = 10 u	1x7 = 7 u		$331

The amount that Ahmad and Charlie each had at first is the same.  Make the amount that they each had the same.  LCM of 7 and 2 is 14.

Amount that Ahmad had more than Charlie in the end
= 10 u - 7 u
= 3 u

3 u = 48

1 u = 48 ÷ 3 = 16

Amount that Ahmad and Charlie had in the end
= 10 u + 7 u
= 17 u
= 17 x 16
= $272

Amount that Jack had in the end
= 331 - 272
= $59

Amount that Jack had at first
= 14 u
= 14 x 16
= $224

Amount that Jack spent
= 224 - 59
= $165

Answer(s): $165