If Vanessa gives Warren $35, the amount of money she has will be 25% of his. If Warren gives Vanessa $19, he will have the same amount of money as her. How much money did each of them have?
(a) Warren
(b) Vanessa

	Case 1		Case 2
	Warren	Vanessa	Warren	Vanessa
Before	4 u - 35	1 u + 35	2.5 u + 19	2.5 u - 19
Change	+ 35	- 35	- 19	+ 19
After	4 u	1 u	2.5 u	2.5 u

(a)
25% = ²⁵₁₀₀ = ¹₄

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

In Case 2, when Warren gives to Vanessa, there is an internal transfer of money from Warren to Vanessa. 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 Vanessa and Warren have
= 4 u + 1 u
= 5 u

Amount that Vanessa and Warren each has in the end for Case 2
= 5 u ÷ 2
= 2.5 u

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

4 u - 35 = 2.5 u + 19
4 u - 2.5 u = 19 + 35
1.5 u = 54 

1 u = 54 ÷ 1.5 = 36

Amount that Warren has
= 4 u - 35
= 4 x 36 - 35
= 144 - 35
= $109 

(b)
Amount that Vanessa has
= 1 u + 35
= 1 x 36 + 35
= 36 + 35
= $71

Answer(s): (a) $109; (b) $71