If Fiona gives Nick $16, the amount of money she has will be 80% of his. If Nick gives Fiona $6, he will have the same amount of money as her. How much money did each of them have?
(a) Nick
(b) Fiona

	Case 1		Case 2
	Nick	Fiona	Nick	Fiona
Before	5 u - 16	4 u + 16	4.5 u + 6	4.5 u - 6
Change	+ 16	- 16	- 6	+ 6
After	5 u	4 u	4.5 u	4.5 u

(a)
80% = ⁸⁰₁₀₀ = ⁴₅

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

In Case 2, when Nick gives to Fiona, there is an internal transfer of money from Nick to Fiona. 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 Fiona and Nick have
= 5 u + 4 u
= 9 u

Amount that Fiona and Nick each has in the end for Case 2
= 9 u ÷ 2
= 4.5 u

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

5 u - 16 = 4.5 u + 6
5 u - 4.5 u = 6 + 16
0.5 u = 22 

1 u = 22 ÷ 0.5 = 44

Amount that Nick has
= 5 u - 16
= 5 x 44 - 16
= 220 - 16
= $204 

(b)
Amount that Fiona has
= 4 u + 16
= 4 x 44 + 16
= 176 + 16
= $192

Answer(s): (a) $204; (b) $192