Risa, Elyse and Kimberly had 1350 cards. Elyse won some of the cards from Risa and as a result, Elyse's cards increased by 25%. Kimberly then won some cards from Elyse and Kimberly's cards increased by 40%. Finally, Kimberly lost some of her cards to Risa and Risa's cards increased by 20%. In the end, they realised that they each had an equal number of cards. How many percent less did Risa have in the end than what she had at first? Correct your answer to 1 decimal place.

Risa	Elyse	Kimberly
1350
	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 = 1350

1 group = 1350 ÷ 3 = 450

1 group = 6 boxes
6 boxes = 450

1 box = 450 ÷ 6 = 75

1 group + 1 box = 7 p
450 + 75 = 7 p
7 p = 525

1 p = 525 ÷ 7 = 75

2 p = 2 x 75 = 150

1 group + 2 p = 5 u
450 + 150 = 5 u
5 u = 600

1 u = 600 ÷ 5 = 120

Number of cards that Risa had at first
= 5 boxes + 1 u
= (5 x 75) + 120
= 375 + 120
= 495

Percent that Risa had less in the end than at first
= ^{495 - 450}₄₉₅ x 100%
≈ 9.1%

Answer(s): 9.1%