Gillian baked 72 macarons. ⁵₈ of the macarons were butter cream macarons. The rest were vanilla macarons. She gave an equal number of butter cream macarons and vanilla macarons away and had 2 times as many butter cream macarons as vanilla macarons left. How many macarons did she give away?

	Butter cream macarons	Vanilla macarons	Difference
Before	5x1 = 5 u	3x1 = 3 u	2x1 = 2 u
Change	- 1 u	- 1 u
After	2x2 = 4 u	1x2 = 2 u	1x2 = 2 u

Since Gillian gave away an equal number of butter cream macarons and vanilla macarons, the difference in the number of butter cream macarons and vanilla macarons remains unchanged.  Make the difference in the butter cream macarons and vanilla macarons the same.  LCM of 2 and 1 is 2.

Total number of macarons at first
= 5 u + 3 u
= 8 u

8 u = 72

1 u = 72 ÷ 8 = 9

Number of macarons that Gillian gave away
= 1 u + 1 u
= 2 u
= 2 x 9 
= 18

Answer(s): 18