If Yoko gives Andy $16, the amount of money she has will be 30% of his. If Andy gives Yoko $68, he will have the same amount of money as her. How much money did each of them have?
(a) Andy
(b) Yoko

	Case 1		Case 2
	Andy	Yoko	Andy	Yoko
Before	10 u - 16	3 u + 16	6.5 u + 68	6.5 u - 68
Change	+ 16	- 16	- 68	+ 68
After	10 u	3 u	6.5 u	6.5 u

(a)
30% = ³⁰₁₀₀ = ³₁₀

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

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

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

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

10 u - 16 = 6.5 u + 68
10 u - 6.5 u = 68 + 16
3.5 u = 84 

1 u = 84 ÷ 3.5 = 24

Amount that Andy has
= 10 u - 16
= 10 x 24 - 16
= 240 - 16
= $224 

(b)
Amount that Yoko has
= 3 u + 16
= 3 x 24 + 16
= 72 + 16
= $88

Answer(s): (a) $224; (b) $88