Wendy and Vanessa have some cookies each. If Wendy gives Vanessa 20 cookies, Wendy will have ¹₂ as many cookies as Vanessa. If Wendy gives Vanessa 15 cookies, they will have an equal number of cookies. How many cookies does Wendy have at first?

	Case 1		Case 2
	Wendy	Vanessa	Wendy	Vanessa
Before	1 u + 20	2 u - 20	1.5 u + 15	1.5 u - 15
Change	- 20	+ 20	- 15	+ 15
After	1 u	2 u	1.5 u	1.5 u

Total number of cookies that Wendy and Vanessa have
= 1 u + 2 u
= 3 u 

Number of cookies that Wendy and Vanessa each has in the end is the same.

Number of cookies that Wendy and Vanessa each has in the end in Case 2
= 3 u ÷ 2
= 1.5 u

Number of cookies that Wendy had at first is the same in Case 1 and Case 2.

1.5 u + 15 = 1 u + 20
1.5 u - 1 u = 20 - 15
0.5 u = 5

1 u = 5 ÷ 0.5 = 10

Number of cookies that Wendy has
= 1 u + 20
= 1 x 10 + 20
= 10 + 20
= 30

Answer(s): 30