Emma used ²₃ of her purple stickers and ³₇ of her white stickers to decorate her diary. In the end, she had an equal number of purple stickers and white stickers left. Given that Emma had a total of 76 purple and white stickers at first, how many white stickers did she use to decorate the diary?

	Purple stickers	White stickers
Before	3x4 = 12 u	7x1 = 7 u
Change	- 2x4 = - 8 u	- 3x1 = - 3 u
After	1x4 = 4 u	4x1 = 4 u

The number of purple stickers and white stickers in the end is the same.  Make the number of purple stickers and white stickers in the end the same.  LCM of 1 and 4 is 4.

Total number of stickers that Emma used to decorate the diary
= 12 u + 7 u
= 19 u

19 u = 76

1 u = 76 ÷ 19 = 4

Number of white stickers that Emma used to decorate the diary
= 3 u
= 3 x 4
= 12

Answer(s): 12