Hilda used ²₃ of her yellow stickers and ²₇ of her grey stickers to decorate her diary. In the end, she had an equal number of yellow stickers and grey stickers left. Given that Hilda had a total of 264 yellow and grey stickers at first, how many grey stickers did she use to decorate the diary?

	Yellow stickers	Grey stickers
Before	3x5 = 15 u	7x1 = 7 u
Change	- 2x5 = - 10 u	- 2x1 = - 2 u
After	1x5 = 5 u	5x1 = 5 u

The number of yellow stickers and grey stickers in the end is the same.  Make the number of yellow stickers and grey stickers in the end the same.  LCM of 1 and 5 is 5.

Total number of stickers that Hilda used to decorate the diary
= 15 u + 7 u
= 22 u

22 u = 264

1 u = 264 ÷ 22 = 12

Number of grey stickers that Hilda used to decorate the diary
= 2 u
= 2 x 12
= 24

Answer(s): 24