Shiyun, Lucy and Emily had 1080 stickers. Lucy won some of the stickers from Shiyun and as a result, Lucy's stickers increased by 25%. Emily then won some stickers from Lucy and Emily's stickers increased by 75%. Finally, Emily lost some of her stickers to Shiyun and Shiyun's stickers increased by 20%. In the end, they realised that they each had an equal number of stickers. How many percent less did Shiyun have in the end than what she had at first? Correct your answer to 1 decimal place.

Shiyun	Lucy	Emily
1080
	4 u
- 1 u	+ 1 u
	5 u
		4 p
	- 3 p	+ 3 p
		7 p
5 boxes
+ 1 box		- 1 box
6 boxes
1 group	1 group	1 group

25% = ²⁵₁₀₀ = ¹₄
75% = ⁷⁵₁₀₀ = ³₄
20% = ²⁰₁₀₀ = ¹₅

Working backwards.

3 groups = 1080

1 group = 1080 ÷ 3 = 360

1 group = 6 boxes
6 boxes = 360

1 box = 360 ÷ 6 = 60

1 group + 1 box = 7 p
360 + 60 = 7 p
7 p = 420

1 p = 420 ÷ 7 = 60

3 p = 3 x 60 = 180

1 group + 3 p = 5 u
360 + 180 = 5 u
5 u = 540

1 u = 540 ÷ 5 = 108

Number of stickers that Shiyun had at first
= 5 boxes + 1 u
= (5 x 60) + 108
= 300 + 108
= 408

Percent that Shiyun had less in the end than at first
= ^{408 - 360}₄₀₈ x 100%
≈ 11.8%

Answer(s): 11.8%