Zara made 14 more coffee biscuits than pandan biscuits. After she gave away ³₅ of the coffee biscuits and ¹₄ of the pandan biscuits, there were an equal number of coffee biscuits and pandan biscuits left. How many coffee biscuits did she give away?

	Coffee biscuits	Pandan biscuits	Difference
Before	5x3 = 15 u	4x2 = 8 u	7 u
Change	- 3x3 = - 9 u	- 1x2 = - 2 u
After	2x3 = 6 u	3x2 = 6 u

Fraction of coffee biscuits left
= 1 - ³₅
= ²₅

Fraction of pandan biscuits left
= 1 - ¹₄
= ³₄

The number of coffee biscuits and pandan biscuits in the end is the same. Make the numerators the same.  LCM of 3 and 2 is 6.

²₅ of coffee biscuits = ³₄ of pandan biscuits
⁶₁₅ of coffee biscuits = ⁶₈ of pandan biscuits

Number of more coffee biscuits than pandan biscuits at first
= 15 u - 8 u
= 7 u

7 u = 14

1 u = 14 ÷ 7 = 2

Number of coffee biscuits that Zara gave away
= 15 u - 6 u
= 9 u
= 9 x 2
= 18

Answer(s): 18