Jean made 100 more mocca biscuits than pandan biscuits. After she gave away ⁴₇ of the mocca biscuits and ¹₈ of the pandan biscuits, there were an equal number of mocca biscuits and pandan biscuits left. How many mocca biscuits did she give away?

	Mocca biscuits	Pandan biscuits	Difference
Before	7x7 = 49 u	8x3 = 24 u	25 u
Change	- 4x7 = - 28 u	- 1x3 = - 3 u
After	3x7 = 21 u	7x3 = 21 u

Fraction of mocca biscuits left
= 1 - ⁴₇
= ³₇

Fraction of pandan biscuits left
= 1 - ¹₈
= ⁷₈

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

³₇ of mocca biscuits = ⁷₈ of pandan biscuits
²¹₄₉ of mocca biscuits = ²¹₂₄ of pandan biscuits

Number of more mocca biscuits than pandan biscuits at first
= 49 u - 24 u
= 25 u

25 u = 100

1 u = 100 ÷ 25 = 4

Number of mocca biscuits that Jean gave away
= 49 u - 21 u
= 28 u
= 28 x 4
= 112

Answer(s): 112