Ivan had some apricot biscuits and cherry biscuits. ²₃ of the number of apricot biscuits was equal to ¹₇ of the number of cherry biscuits. After Ivan made 16 more apricot biscuits, the number of apricot biscuits was ¹₂ of the number of cherry biscuits. How many biscuits did he have altogether in the end?
Make the numerators the same. LCM of 2 and 1 is 2.

23 of apricot biscuits = 1x27x2 of cherry biscuits

²₃ of apricot biscuits = ²₁₄ of cherry biscuits

	Apricot biscuits	Cherry biscuits	Total
Before	3 u	14 u
Change	+ 16
After	1x7 = 7 u	2x7 = 14 u	21 u

The number of cherry biscuits remains unchanged.  Make the number of cherry biscuits the same.  LCM of 2 and 14 is 14.

Number of more apricot biscuits made
= 7 u - 3 u
= 4 u

4 u = 16

1 u = 16 ÷ 4 = 4

Number of biscuits that Ivan had in the end
= 7 u + 14 u
= 21 u
= 21 x 4
= 84

Answer(s): 84