If Cindy gives Lee $27, the amount of money she has will be 30% of his. If Lee gives Cindy $85, he will have the same amount of money as her. How much money did each of them have?
(a) Lee
(b) Cindy

	Case 1		Case 2
	Lee	Cindy	Lee	Cindy
Before	10 u - 27	3 u + 27	6.5 u + 85	6.5 u - 85
Change	+ 27	- 27	- 85	+ 85
After	10 u	3 u	6.5 u	6.5 u

(a)
30% = ³⁰₁₀₀ = ³₁₀

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

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

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

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

10 u - 27 = 6.5 u + 85
10 u - 6.5 u = 85 + 27
3.5 u = 112 

1 u = 112 ÷ 3.5 = 32

Amount that Lee has
= 10 u - 27
= 10 x 32 - 27
= 320 - 27
= $293 

(b)
Amount that Cindy has
= 3 u + 27
= 3 x 32 + 27
= 96 + 27
= $123

Answer(s): (a) $293; (b) $123