Shannon made puffs for sale. 40% of the puffs were curry puffs and the rest were chocolate and beef puffs in the ratio 3 : 1. If a customer bought 60% of the curry puffs and all of the beef puffs, what percentage of the chocolate puffs must Shannon sell for her to maintain the original percentage of curry puffs at first? Leave your answer in decimals and correct to 1 decimal place.

Curry puffs	Chocolate puffs	Beef puffs
2 u	3 u
	2.25 u	0.75 u

	Curry puffs	Chocolate puffs	Beef puffs	Total puffs
Before	2 u	2.25 u	0.75 u	5 u
Change	- 1.2 u	- 1.05 u	- 0.75 u
After	0.8 u	1.2 u	0	2 u

40% = ⁴⁰₁₀₀ = ²₅
60% = ⁶⁰₁₀₀ = ³₅

Total number of puffs = 5 u

Number of chocolate and beef puffs
= 5 u - 2 u
= 3 u

Number of chocolate puffs at first
= ³₄ x 3 u
= 2.25 u

Number of beef puffs at first
= 3 u - 2.25 u
= 0.75 u

Number of curry puffs sold
= 60% x 2 u
= ⁶⁰₁₀₀ x 2 u
= ³₅ x 2 u
= 1.2 u

Number of beef puffs sold
= ¹₄ x 3 u
= 0.75 u

Number of curry puffs left 
= 2 u - 1.2 u
= 0.8 u

To maintain the percentage of the curry puffs in the end, 
40% → 0.8 u
100% → ^0.8₄₀ x 100 = 2 u

Total number of puffs in the end to maintain the original percentage of curry puffs = 2 u

Number of chocolate puffs left
= 2 u - 0.8 u
= 1.2 u

Number of chocolate puffs that Shannon must sell to maintain the original percentage of curry puffs
= 2.25 u - 1.2 u
= 1.05 u

Percentage of the chocolate puffs that Shannon must sell
= ^1.05_2.25 x 100%
= 46.7%

Answer(s): 46.7%