Risa, Shannon and Fiona had 630 cards. Shannon won some of the cards from Risa and as a result, Shannon's cards increased by 20%. Fiona then won some cards from Shannon and Fiona's cards increased by 40%. Finally, Fiona lost some of her cards to Risa and Risa's cards increased by 25%. 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	Shannon	Fiona
630
	5 u
- 1 u	+ 1 u
	6 u
		5 p
	- 2 p	+ 2 p
		7 p
4 boxes
+ 1 box		- 1 box
5 boxes
1 group	1 group	1 group

20% = ²⁰₁₀₀ = ¹₅
40% = ⁴⁰₁₀₀ = ²₅
25% = ²⁵₁₀₀ = ¹₄

Working backwards.

3 groups = 630

1 group = 630 ÷ 3 = 210

1 group = 5 boxes
5 boxes = 210

1 box = 210 ÷ 5 = 42

1 group + 1 box = 7 p
210 + 42 = 7 p
7 p = 252

1 p = 252 ÷ 7 = 36

2 p = 2 x 36 = 72

1 group + 2 p = 6 u
210 + 72 = 6 u
6 u = 282

1 u = 282 ÷ 6 = 47

Number of cards that Risa had at first
= 4 boxes + 1 u
= (4 x 42) + 47
= 168 + 47
= 215

Percent that Risa had less in the end than at first
= ^{215 - 210}₂₁₅ x 100%
≈ 2.3%

Answer(s): 2.3%