If Anna gives Andy $18, the amount of money she has will be 40% of his. If Andy gives Anna $48, he will have the same amount of money as her. How much money did each of them have?
(a) Andy
(b) Anna

	Case 1		Case 2
	Andy	Anna	Andy	Anna
Before	5 u - 18	2 u + 18	3.5 u + 48	3.5 u - 48
Change	+ 18	- 18	- 48	+ 48
After	5 u	2 u	3.5 u	3.5 u

(a)
40% = ⁴⁰₁₀₀ = ²₅

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

In Case 2, when Andy gives to Anna, there is an internal transfer of money from Andy to Anna. 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 Anna and Andy have
= 5 u + 2 u
= 7 u

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

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

5 u - 18 = 3.5 u + 48
5 u - 3.5 u = 48 + 18
1.5 u = 66 

1 u = 66 ÷ 1.5 = 44

Amount that Andy has
= 5 u - 18
= 5 x 44 - 18
= 220 - 18
= $202 

(b)
Amount that Anna has
= 2 u + 18
= 2 x 44 + 18
= 88 + 18
= $106

Answer(s): (a) $202; (b) $106