Anna, Pamela and Victoria had 756 pens. Pamela won some of the pens from Anna and as a result, Pamela's pens increased by 50%. Victoria then won some pens from Pamela and Victoria's pens increased by 75%. Finally, Victoria lost some of her pens to Anna and Anna's pens increased by 20%. In the end, they realised that they each had an equal number of pens. How many percent less did Anna have in the end than what she had at first? Correct your answer to 1 decimal place.

Anna	Pamela	Victoria
756
	2 u
- 1 u	+ 1 u
	3 u
		4 p
	- 3 p	+ 3 p
		7 p
5 boxes
+ 1 box		- 1 box
6 boxes
1 group	1 group	1 group

50% = ⁵⁰₁₀₀ = ¹₂
75% = ⁷⁵₁₀₀ = ³₄
20% = ²⁰₁₀₀ = ¹₅

Working backwards.

3 groups = 756

1 group = 756 ÷ 3 = 252

1 group = 6 boxes
6 boxes = 252

1 box = 252 ÷ 6 = 42

1 group + 1 box = 7 p
252 + 42 = 7 p
7 p = 294

1 p = 294 ÷ 7 = 42

3 p = 3 x 42 = 126

1 group + 3 p = 3 u
252 + 126 = 3 u
3 u = 378

1 u = 378 ÷ 3 = 126

Number of pens that Anna had at first
= 5 boxes + 1 u
= (5 x 42) + 126
= 210 + 126
= 336

Percent that Anna had less in the end than at first
= ^{336 - 252}₃₃₆ x 100%
≈ 25.0%

Answer(s): 25.0%