Penelope and Shannon have some tarts each. If Penelope gives Shannon 20 tarts, Penelope will have ²₅ as many tarts as Shannon. If Penelope gives Shannon 9 tarts, they will have an equal number of tarts. How many tarts does Shannon have at first?

	Case 1		Case 2
	Penelope	Shannon	Penelope	Shannon
Before	2 u + 20	5 u - 20	3.5 u + 9	3.5 u - 9
Change	- 20	+ 20	- 9	+ 9
After	2 u	5 u	3.5 u	3.5 u

Total number of tarts that Penelope and Shannon have
= 2 u + 5 u
= 7 u 

Number of tarts that Penelope and Shannon each has in the end is the same.

Number of tarts that Penelope and Shannon each has in the end in Case 2
= 7 u ÷ 2
= 3.5 u

Number of tarts that Penelope had at first is the same in Case 1 and Case 2.

3.5 u + 9 = 2 u + 20
3.5 u - 2 u = 20 - 9
0.5 u = 11

1 u = 11 ÷ 0.5 = 22

Number of tarts that Shannon has
= 5 u - 20
= 5 x 22 - 20
= 110 - 20
= 90

Answer(s): 90