At first, Ahmad, George and Ben had the same amount of money. After Ben spent some of his money, Ahmad spent ³₅ of his money and George spent ³₄ of his money, Ahmad had $30 more than George. In the end, the total amount of money the three boys had left was $162. How much money did Ben spend?

	Ahmad	George	Ben	Total
Before	5x4 =  20 u	4x5 = 20 u	20 u
Change	- 3x4 = - 12 u	- 3x5 = - 15 u	- ?
After	2x4 = 8 u	1x5 = 5 u		$162

The amount that Ahmad and George each had at first is the same.  Make the amount that they each had the same.  LCM of 5 and 4 is 20.

Amount that Ahmad had more than George in the end
= 8 u - 5 u
= 3 u

3 u = 30

1 u = 30 ÷ 3 = 10

Amount that Ahmad and George had in the end
= 8 u + 5 u
= 13 u
= 13 x 10
= $130

Amount that Ben had in the end
= 162 - 130
= $32

Amount that Ben had at first
= 20 u
= 20 x 10
= $200

Amount that Ben spent
= 200 - 32
= $168

Answer(s): $168