Eva used ²₇ of her blue stickers and ²₅ of her purple stickers to decorate her diary. In the end, she had an equal number of blue stickers and purple stickers left. Given that Eva had a total of 276 blue and purple stickers at first, how many purple stickers did she use to decorate the diary?

	Blue stickers	Purple stickers
Before	7x3 = 21 u	5x5 = 25 u
Change	- 2x3 = - 6 u	- 2x5 = - 10 u
After	5x3 = 15 u	3x5 = 15 u

The number of blue stickers and purple stickers in the end is the same.  Make the number of blue stickers and purple stickers in the end the same.  LCM of 5 and 3 is 15.

Total number of stickers that Eva used to decorate the diary
= 21 u + 25 u
= 46 u

46 u = 276

1 u = 276 ÷ 46 = 6

Number of purple stickers that Eva used to decorate the diary
= 10 u
= 10 x 6
= 60

Answer(s): 60