Zane had some chocolate chip tarts and blueberry tarts. ³₅ of the number of chocolate chip tarts was equal to ¹₃ of the number of blueberry tarts. After Zane made 12 more chocolate chip tarts, the number of chocolate chip tarts was ²₃ of the number of blueberry tarts. How many tarts did he have altogether in the end?
Make the numerators the same. LCM of 3 and 1 is 3.

35 of chocolate chip tarts = 1x33x3 of blueberry tarts

³₅ of chocolate chip tarts = ³₉ of blueberry tarts

	Chocolate chip tarts	Blueberry tarts	Total
Before	5 u	9 u
Change	+ 12
After	2x3 = 6 u	3x3 = 9 u	15 u

The number of blueberry tarts remains unchanged.  Make the number of blueberry tarts the same.  LCM of 3 and 9 is 9.

Number of more chocolate chip tarts made
= 6 u - 5 u
= 1 u

1 u = 12

1 u = 12 ÷ 1 = 12

Number of tarts that Zane had in the end
= 6 u + 9 u
= 15 u
= 15 x 12
= 180

Answer(s): 180