Emily, Nora and Irene had 1260 erasers. Nora won some of the erasers from Emily and as a result, Nora's erasers increased by 50%. Irene then won some erasers from Nora and Irene's erasers increased by 60%. Finally, Irene lost some of her erasers to Emily and Emily's erasers increased by 25%. In the end, they realised that they each had an equal number of erasers. How many percent less did Emily have in the end than what she had at first? Correct your answer to 1 decimal place.

Emily	Nora	Irene
1260
	2 u
- 1 u	+ 1 u
	3 u
		5 p
	- 3 p	+ 3 p
		8 p
4 boxes
+ 1 box		- 1 box
5 boxes
1 group	1 group	1 group

50% = ⁵⁰₁₀₀ = ¹₂
60% = ⁶⁰₁₀₀ = ³₅
25% = ²⁵₁₀₀ = ¹₄

Working backwards.

3 groups = 1260

1 group = 1260 ÷ 3 = 420

1 group = 5 boxes
5 boxes = 420

1 box = 420 ÷ 5 = 84

1 group + 1 box = 8 p
420 + 84 = 8 p
8 p = 504

1 p = 504 ÷ 8 = 63

3 p = 3 x 63 = 189

1 group + 3 p = 3 u
420 + 189 = 3 u
3 u = 609

1 u = 609 ÷ 3 = 203

Number of erasers that Emily had at first
= 4 boxes + 1 u
= (4 x 84) + 203
= 336 + 203
= 539

Percent that Emily had less in the end than at first
= ^{539 - 420}₅₃₉ x 100%
≈ 22.1%

Answer(s): 22.1%