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

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

	Beef puffs	Chicken puffs	Curry 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 chicken and curry puffs
= 5 u - 2 u
= 3 u

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

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

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

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

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

To maintain the percentage of the beef 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 beef puffs = 2 u

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

Number of chicken puffs that Yen must sell to maintain the original percentage of beef puffs
= 2.25 u - 1.2 u
= 1.05 u

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

Answer(s): 46.7%