If Yoko gives Perry $17, the amount of money she has will be 30% of his. If Perry gives Yoko $116, he will have the same amount of money as her. How much money did each of them have?
(a) Perry
(b) Yoko

	Case 1		Case 2
	Perry	Yoko	Perry	Yoko
Before	10 u - 17	3 u + 17	6.5 u + 116	6.5 u - 116
Change	+ 17	- 17	- 116	+ 116
After	10 u	3 u	6.5 u	6.5 u

(a)
30% = ³⁰₁₀₀ = ³₁₀

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

In Case 2, when Perry gives to Yoko, there is an internal transfer of money from Perry to Yoko. 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 Yoko and Perry have
= 10 u + 3 u
= 13 u

Amount that Yoko and Perry each has in the end for Case 2
= 13 u ÷ 2
= 6.5 u

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

10 u - 17 = 6.5 u + 116
10 u - 6.5 u = 116 + 17
3.5 u = 133 

1 u = 133 ÷ 3.5 = 38

Amount that Perry has
= 10 u - 17
= 10 x 38 - 17
= 380 - 17
= $363 

(b)
Amount that Yoko has
= 3 u + 17
= 3 x 38 + 17
= 114 + 17
= $131

Answer(s): (a) $363; (b) $131