Shiyun baked 165 cookies. ³₅ of the cookies were vanilla cookies. The rest were chocolate cookies. She gave an equal number of vanilla cookies and chocolate cookies away and had 4 times as many vanilla cookies as chocolate cookies left. How many cookies did she give away?

	Vanilla cookies	Chocolate cookies	Difference
Before	3x3 = 9 u	2x3 = 6 u	1x3 = 3 u
Change	- 5 u	- 5 u
After	4x1 = 4 u	1x1 = 1 u	3x1 = 3 u

Since Shiyun gave away an equal number of vanilla cookies and chocolate cookies, the difference in the number of vanilla cookies and chocolate cookies remains unchanged.  Make the difference in the vanilla cookies and chocolate cookies the same.  LCM of 1 and 3 is 3.

Total number of cookies at first
= 9 u + 6 u
= 15 u

15 u = 165

1 u = 165 ÷ 15 = 11

Number of cookies that Shiyun gave away
= 5 u + 5 u
= 10 u
= 10 x 11 
= 110

Answer(s): 110