Risa made 121 more mocca puffs than apple puffs. After she gave away ²₅ of the mocca puffs and ¹₈ of the apple puffs, there were an equal number of mocca puffs and apple puffs left. How many mocca puffs did she give away?

	Mocca puffs	Apple 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 mocca puffs left
= 1 - ²₅
= ³₅

Fraction of apple puffs left
= 1 - ¹₈
= ⁷₈

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

³₅ of mocca puffs = ⁷₈ of apple puffs
²¹₃₅ of mocca puffs = ²¹₂₄ of apple puffs

Number of more mocca puffs than apple puffs at first
= 35 u - 24 u
= 11 u

11 u = 121

1 u = 121 ÷ 11 = 11

Number of mocca puffs that Risa gave away
= 35 u - 21 u
= 14 u
= 14 x 11
= 154

Answer(s): 154