If Lynn gives Carl $16, the amount of money she has will be 75% of his. If Carl gives Lynn $5, he will have the same amount of money as her. How much money did each of them have?
(a) Carl
(b) Lynn

	Case 1		Case 2
	Carl	Lynn	Carl	Lynn
Before	4 u - 16	3 u + 16	3.5 u + 5	3.5 u - 5
Change	+ 16	- 16	- 5	+ 5
After	4 u	3 u	3.5 u	3.5 u

(a)
75% = ⁷⁵₁₀₀ = ³₄

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

In Case 2, when Carl gives to Lynn, there is an internal transfer of money from Carl to Lynn. 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 Lynn and Carl have
= 4 u + 3 u
= 7 u

Amount that Lynn and Carl each has in the end for Case 2
= 7 u ÷ 2
= 3.5 u

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

4 u - 16 = 3.5 u + 5
4 u - 3.5 u = 5 + 16
0.5 u = 21 

1 u = 21 ÷ 0.5 = 42

Amount that Carl has
= 4 u - 16
= 4 x 42 - 16
= 168 - 16
= $152 

(b)
Amount that Lynn has
= 3 u + 16
= 3 x 42 + 16
= 126 + 16
= $142

Answer(s): (a) $152; (b) $142