Zoe baked 70 biscuits. ³₅ of the biscuits were peach biscuits. The rest were strawberry biscuits. She gave an equal number of peach biscuits and strawberry biscuits away and had 3 times as many peach biscuits as strawberry biscuits left. How many biscuits did she give away?

	Peach biscuits	Strawberry biscuits	Difference
Before	3x2 = 6 u	2x2 = 4 u	1x2 = 2 u
Change	- 3 u	- 3 u
After	3x1 = 3 u	1x1 = 1 u	2x1 = 2 u

Since Zoe gave away an equal number of peach biscuits and strawberry biscuits, the difference in the number of peach biscuits and strawberry biscuits remains unchanged.  Make the difference in the peach biscuits and strawberry biscuits the same.  LCM of 1 and 2 is 2.

Total number of biscuits at first
= 6 u + 4 u
= 10 u

10 u = 70

1 u = 70 ÷ 10 = 7

Number of biscuits that Zoe gave away
= 3 u + 3 u
= 6 u
= 6 x 7 
= 42

Answer(s): 42