Fiona made 66 more pandan puffs than durian puffs. After she gave away ²₅ of the pandan puffs and ¹₈ of the durian puffs, there were an equal number of pandan puffs and durian puffs left. How many pandan puffs did she give away?

	Pandan puffs	Durian puffs	Difference
Before	5x7 = 35 u	8x3 = 24 u	11 u
Change	- 2x7 = - 14 u	- 1x3 = - 3 u
After	3x7 = 21 u	7x3 = 21 u

Fraction of pandan puffs left
= 1 - ²₅
= ³₅

Fraction of durian puffs left
= 1 - ¹₈
= ⁷₈

The number of pandan puffs and durian puffs in the end is the same. Make the numerators the same.  LCM of 7 and 3 is 21.

³₅ of pandan puffs = ⁷₈ of durian puffs
²¹₃₅ of pandan puffs = ²¹₂₄ of durian puffs

Number of more pandan puffs than durian puffs at first
= 35 u - 24 u
= 11 u

11 u = 66

1 u = 66 ÷ 11 = 6

Number of pandan puffs that Fiona gave away
= 35 u - 21 u
= 14 u
= 14 x 6
= 84

Answer(s): 84