Kathy used ²₅ of her black stickers and ³₅ of her white stickers to decorate her diary. In the end, she had an equal number of black stickers and white stickers left. Given that Kathy had a total of 275 black and white stickers at first, how many white stickers did she use to decorate the diary?

	Black stickers	White stickers
Before	5x2 = 10 u	5x3 = 15 u
Change	- 2x2 = - 4 u	- 3x3 = - 9 u
After	3x2 = 6 u	2x3 = 6 u

The number of black stickers and white stickers in the end is the same.  Make the number of black stickers and white stickers in the end the same.  LCM of 3 and 2 is 6.

Total number of stickers that Kathy used to decorate the diary
= 10 u + 15 u
= 25 u

25 u = 275

1 u = 275 ÷ 25 = 11

Number of white stickers that Kathy used to decorate the diary
= 9 u
= 9 x 11
= 99

Answer(s): 99