If Erika gives Justin $35, the amount of money she has will be 10% of his. If Justin gives Erika $181, he will have the same amount of money as her. How much money did each of them have?
(a) Justin
(b) Erika

	Case 1		Case 2
	Justin	Erika	Justin	Erika
Before	10 u - 35	1 u + 35	5.5 u + 181	5.5 u - 181
Change	+ 35	- 35	- 181	+ 181
After	10 u	1 u	5.5 u	5.5 u

(a)
10% = ¹⁰₁₀₀ = ¹₁₀

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

In Case 2, when Justin gives to Erika, there is an internal transfer of money from Justin to Erika. 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 Erika and Justin have
= 10 u + 1 u
= 11 u

Amount that Erika and Justin each has in the end for Case 2
= 11 u ÷ 2
= 5.5 u

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

10 u - 35 = 5.5 u + 181
10 u - 5.5 u = 181 + 35
4.5 u = 216 

1 u = 216 ÷ 4.5 = 48

Amount that Justin has
= 10 u - 35
= 10 x 48 - 35
= 480 - 35
= $445 

(b)
Amount that Erika has
= 1 u + 35
= 1 x 48 + 35
= 48 + 35
= $83

Answer(s): (a) $445; (b) $83