If Wendy gives George $25, the amount of money she has will be 10% of his. If George gives Wendy $128, he will have the same amount of money as her. How much money did each of them have?
(a) George
(b) Wendy

	Case 1		Case 2
	George	Wendy	George	Wendy
Before	10 u - 25	1 u + 25	5.5 u + 128	5.5 u - 128
Change	+ 25	- 25	- 128	+ 128
After	10 u	1 u	5.5 u	5.5 u

(a)
10% = ¹⁰₁₀₀ = ¹₁₀

In Case 1, when Wendy gives to George, there is an internal transfer of money from Wendy to George.  The total amount that both have remains the same.

In Case 2, when George gives to Wendy, there is an internal transfer of money from George to Wendy. The total amount that both have remains the same.

The total amount that both have in Case 1 and Case 2 are the same.

Total amount that Wendy and George have
= 10 u + 1 u
= 11 u

Amount that Wendy and George each has in the end for Case 2
= 11 u ÷ 2
= 5.5 u

Amount that George has at first is the same in Case 1 and Case 2.

10 u - 25 = 5.5 u + 128
10 u - 5.5 u = 128 + 25
4.5 u = 153 

1 u = 153 ÷ 4.5 = 34

Amount that George has
= 10 u - 25
= 10 x 34 - 25
= 340 - 25
= $315 

(b)
Amount that Wendy has
= 1 u + 25
= 1 x 34 + 25
= 34 + 25
= $59

Answer(s): (a) $315; (b) $59