Xylia made 12 more strawberry biscuits than banana biscuits. After she gave away ²₇ of the strawberry biscuits and ¹₅ of the banana biscuits, there were an equal number of strawberry biscuits and banana biscuits left. How many strawberry biscuits did she give away?

	Strawberry biscuits	Banana biscuits	Difference
Before	7x4 = 28 u	5x5 = 25 u	3 u
Change	- 2x4 = - 8 u	- 1x5 = - 5 u
After	5x4 = 20 u	4x5 = 20 u

Fraction of strawberry biscuits left
= 1 - ²₇
= ⁵₇

Fraction of banana biscuits left
= 1 - ¹₅
= ⁴₅

The number of strawberry biscuits and banana biscuits in the end is the same. Make the numerators the same.  LCM of 4 and 5 is 20.

⁵₇ of strawberry biscuits = ⁴₅ of banana biscuits
²⁰₂₈ of strawberry biscuits = ²⁰₂₅ of banana biscuits

Number of more strawberry biscuits than banana biscuits at first
= 28 u - 25 u
= 3 u

3 u = 12

1 u = 12 ÷ 3 = 4

Number of strawberry biscuits that Xylia gave away
= 28 u - 20 u
= 8 u
= 8 x 4
= 32

Answer(s): 32