Lucy made 40 more blueberry croissants than strawberry croissants. After she gave away ⁴₇ of the blueberry croissants and ¹₃ of the strawberry croissants, there were an equal number of blueberry croissants and strawberry croissants left. How many blueberry croissants did she give away?

	Blueberry croissants	Strawberry croissants	Difference
Before	7x2 = 14 u	3x3 = 9 u	5 u
Change	- 4x2 = - 8 u	- 1x3 = - 3 u
After	3x2 = 6 u	2x3 = 6 u

Fraction of blueberry croissants left
= 1 - ⁴₇
= ³₇

Fraction of strawberry croissants left
= 1 - ¹₃
= ²₃

The number of blueberry croissants and strawberry croissants in the end is the same. Make the numerators the same.  LCM of 2 and 3 is 6.

³₇ of blueberry croissants = ²₃ of strawberry croissants
⁶₁₄ of blueberry croissants = ⁶₉ of strawberry croissants

Number of more blueberry croissants than strawberry croissants at first
= 14 u - 9 u
= 5 u

5 u = 40

1 u = 40 ÷ 5 = 8

Number of blueberry croissants that Lucy gave away
= 14 u - 6 u
= 8 u
= 8 x 8
= 64

Answer(s): 64