SOLUTION: Alvin had $250 more than Shufun. After both had spent 1/2 of what they had, the ratio of Alvin’s money to Shufun became 3:2. Alvin then gave Shufun money to make the new ratio 9:16

let original amount Alvin had, be A
Then original amount Shufun had = A - 250
After spending  of his money, Alvin had: 
After spending  of his money, Shufun had: 
We then get: 
				
				
3(A - 250) = 2A ------- Cross-multiplying				
3A - 750 = 2A
- 750 = 2A - 3A
- 750 = - A

Shufun's original amount: 750 - 250 = $500

Since Alvin had $750, originally, and spent , or $375, he then had $375 left
Since Shufun had $500, originally, and spent , or $250, he then had $250 left

Let the amount Alvin gave Shufun, be y. We get the following equation:				

9(250 + y) = 16(375 - y) ------- Cross-multiplying	
2,250 + 9y = 6,000 - 16y
9y + 16y = 6,000 - 2,250
25y = 3,750			
Amount given to Shufun by Alvin, or