Anna used ⁵₇ of her green stickers and ²₇ of her yellow stickers to decorate her diary. In the end, she had an equal number of green stickers and yellow stickers left. Given that Anna had a total of 343 green and yellow stickers at first, how many yellow stickers did she use to decorate the diary?

	Green stickers	Yellow stickers
Before	7x5 = 35 u	7x2 = 14 u
Change	- 5x5 = - 25 u	- 2x2 = - 4 u
After	2x5 = 10 u	5x2 = 10 u

The number of green stickers and yellow stickers in the end is the same.  Make the number of green stickers and yellow stickers in the end the same.  LCM of 2 and 5 is 10.

Total number of stickers that Anna used to decorate the diary
= 35 u + 14 u
= 49 u

49 u = 343

1 u = 343 ÷ 49 = 7

Number of yellow stickers that Anna used to decorate the diary
= 4 u
= 4 x 7
= 28

Answer(s): 28