Dylan had some apple croissants and chocolate chip croissants. ⁵₉ of the number of apple croissants was equal to ¹₃ of the number of chocolate chip croissants. After Dylan made 21 more apple croissants, the number of apple croissants was ⁴₅ of the number of chocolate chip croissants. How many croissants did he have altogether in the end?
Make the numerators the same. LCM of 5 and 1 is 5.

59 of apple croissants = 1x53x5 of chocolate chip croissants

⁵₉ of apple croissants = ⁵₁₅ of chocolate chip croissants

	Apple croissants	Chocolate chip croissants	Total
Before	9 u	15 u
Change	+ 21
After	4x3 = 12 u	5x3 = 15 u	27 u

The number of chocolate chip croissants remains unchanged.  Make the number of chocolate chip croissants the same.  LCM of 5 and 15 is 15.

Number of more apple croissants made
= 12 u - 9 u
= 3 u

3 u = 21

1 u = 21 ÷ 3 = 7

Number of croissants that Dylan had in the end
= 12 u + 15 u
= 27 u
= 27 x 7
= 189

Answer(s): 189