Lynn, Kylie and Barbara had 702 pens. Kylie won some of the pens from Lynn and as a result, Kylie's pens increased by 50%. Barbara then won some pens from Kylie and Barbara's pens increased by 40%. Finally, Barbara lost some of her pens to Lynn and Lynn's pens increased by 20%. In the end, they realised that they each had an equal number of pens. How many percent less did Lynn have in the end than what she had at first? Correct your answer to 1 decimal place.

Lynn	Kylie	Barbara
702
	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 = 702

1 group = 702 ÷ 3 = 234

1 group = 6 boxes
6 boxes = 234

1 box = 234 ÷ 6 = 39

1 group + 1 box = 7 p
234 + 39 = 7 p
7 p = 273

1 p = 273 ÷ 7 = 39

2 p = 2 x 39 = 78

1 group + 2 p = 3 u
234 + 78 = 3 u
3 u = 312

1 u = 312 ÷ 3 = 104

Number of pens that Lynn had at first
= 5 boxes + 1 u
= (5 x 39) + 104
= 195 + 104
= 299

Percent that Lynn had less in the end than at first
= ^{299 - 234}₂₉₉ x 100%
≈ 21.7%

Answer(s): 21.7%