Rachel used ²₅ of her green stickers and ³₅ of her brown stickers to decorate her diary. In the end, she had an equal number of green stickers and brown stickers left. Given that Rachel had a total of 225 green and brown stickers at first, how many brown stickers did she use to decorate the diary?

	Green stickers	Brown 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 green stickers and brown stickers in the end is the same.  Make the number of green stickers and brown stickers in the end the same.  LCM of 3 and 2 is 6.

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

25 u = 225

1 u = 225 ÷ 25 = 9

Number of brown stickers that Rachel used to decorate the diary
= 9 u
= 9 x 9
= 81

Answer(s): 81