Kylie and Gillian have some cookies each. If Kylie gives Gillian 19 cookies, Kylie will have ²₇ as many cookies as Gillian. If Kylie gives Gillian 4 cookies, they will have an equal number of cookies. How many cookies does Gillian have at first?

	Case 1		Case 2
	Kylie	Gillian	Kylie	Gillian
Before	2 u + 19	7 u - 19	4.5 u + 4	4.5 u - 4
Change	- 19	+ 19	- 4	+ 4
After	2 u	7 u	4.5 u	4.5 u

Total number of cookies that Kylie and Gillian have
= 2 u + 7 u
= 9 u 

Number of cookies that Kylie and Gillian each has in the end is the same.

Number of cookies that Kylie and Gillian each has in the end in Case 2
= 9 u ÷ 2
= 4.5 u

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

4.5 u + 4 = 2 u + 19
4.5 u - 2 u = 19 - 4
0.5 u = 15

1 u = 15 ÷ 0.5 = 30

Number of cookies that Gillian has
= 7 u - 19
= 7 x 30 - 19
= 210 - 19
= 191

Answer(s): 191