Marion, Lucy and Nora had 990 stickers. Lucy won some of the stickers from Marion and as a result, Lucy's stickers increased by 25%. Nora then won some stickers from Lucy and Nora's stickers increased by 40%. Finally, Nora lost some of her stickers to Marion and Marion's stickers increased by 20%. In the end, they realised that they each had an equal number of stickers. How many percent less did Marion have in the end than what she had at first? Correct your answer to 1 decimal place.

Marion	Lucy	Nora
990
	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 = 990

1 group = 990 ÷ 3 = 330

1 group = 6 boxes
6 boxes = 330

1 box = 330 ÷ 6 = 55

1 group + 1 box = 7 p
330 + 55 = 7 p
7 p = 385

1 p = 385 ÷ 7 = 55

2 p = 2 x 55 = 110

1 group + 2 p = 5 u
330 + 110 = 5 u
5 u = 440

1 u = 440 ÷ 5 = 88

Number of stickers that Marion had at first
= 5 boxes + 1 u
= (5 x 55) + 88
= 275 + 88
= 363

Percent that Marion had less in the end than at first
= ^{363 - 330}₃₆₃ x 100%
≈ 9.1%

Answer(s): 9.1%