Pierre had some chocolate chip muffins and blueberry muffins. ⁵₇ of the number of chocolate chip muffins was equal to ¹₈ of the number of blueberry muffins. After Pierre made 108 more chocolate chip muffins, the number of chocolate chip muffins was ²₅ of the number of blueberry muffins. How many muffins did he have altogether in the end?
Make the numerators the same. LCM of 5 and 1 is 5.

57 of chocolate chip muffins = 1x58x5 of blueberry muffins

⁵₇ of chocolate chip muffins = ⁵₄₀ of blueberry muffins

	Chocolate chip muffins	Blueberry muffins	Total
Before	7 u	40 u
Change	+ 108
After	2x8 = 16 u	5x8 = 40 u	56 u

The number of blueberry muffins remains unchanged.  Make the number of blueberry muffins the same.  LCM of 5 and 40 is 40.

Number of more chocolate chip muffins made
= 16 u - 7 u
= 9 u

9 u = 108

1 u = 108 ÷ 9 = 12

Number of muffins that Pierre had in the end
= 16 u + 40 u
= 56 u
= 56 x 12
= 672

Answer(s): 672