Emma, Nicole and Anna had 1188 erasers. Nicole won some of the erasers from Emma and as a result, Nicole's erasers increased by 50%. Anna then won some erasers from Nicole and Anna's erasers increased by 40%. Finally, Anna lost some of her erasers to Emma and Emma's erasers increased by 20%. In the end, they realised that they each had an equal number of erasers. How many percent less did Emma have in the end than what she had at first? Correct your answer to 1 decimal place.

Emma	Nicole	Anna
1188
	2 u
- 1 u	+ 1 u
	3 u
		5 p
	- 2 p	+ 2 p
		7 p
5 boxes
+ 1 box		- 1 box
6 boxes
1 group	1 group	1 group

50% = ⁵⁰₁₀₀ = ¹₂
40% = ⁴⁰₁₀₀ = ²₅
20% = ²⁰₁₀₀ = ¹₅

Working backwards.

3 groups = 1188

1 group = 1188 ÷ 3 = 396

1 group = 6 boxes
6 boxes = 396

1 box = 396 ÷ 6 = 66

1 group + 1 box = 7 p
396 + 66 = 7 p
7 p = 462

1 p = 462 ÷ 7 = 66

2 p = 2 x 66 = 132

1 group + 2 p = 3 u
396 + 132 = 3 u
3 u = 528

1 u = 528 ÷ 3 = 176

Number of erasers that Emma had at first
= 5 boxes + 1 u
= (5 x 66) + 176
= 330 + 176
= 506

Percent that Emma had less in the end than at first
= ^{506 - 396}₅₀₆ x 100%
≈ 21.7%

Answer(s): 21.7%