Opal, Gwen and Jane had 810 stickers. Gwen won some of the stickers from Opal and as a result, Gwen's stickers increased by 25%. Jane then won some stickers from Gwen and Jane's stickers increased by 40%. Finally, Jane lost some of her stickers to Opal and Opal's stickers increased by 20%. In the end, they realised that they each had an equal number of stickers. How many percent less did Opal have in the end than what she had at first? Correct your answer to 1 decimal place.

Opal	Gwen	Jane
810
	4 u
- 1 u	+ 1 u
	5 u
		5 p
	- 2 p	+ 2 p
		7 p
5 boxes
+ 1 box		- 1 box
6 boxes
1 group	1 group	1 group

25% = ²⁵₁₀₀ = ¹₄
40% = ⁴⁰₁₀₀ = ²₅
20% = ²⁰₁₀₀ = ¹₅

Working backwards.

3 groups = 810

1 group = 810 ÷ 3 = 270

1 group = 6 boxes
6 boxes = 270

1 box = 270 ÷ 6 = 45

1 group + 1 box = 7 p
270 + 45 = 7 p
7 p = 315

1 p = 315 ÷ 7 = 45

2 p = 2 x 45 = 90

1 group + 2 p = 5 u
270 + 90 = 5 u
5 u = 360

1 u = 360 ÷ 5 = 72

Number of stickers that Opal had at first
= 5 boxes + 1 u
= (5 x 45) + 72
= 225 + 72
= 297

Percent that Opal had less in the end than at first
= ^{297 - 270}₂₉₇ x 100%
≈ 9.1%

Answer(s): 9.1%