Jen made puffs for sale. 40% of the puffs were lotus paste puffs and the rest were beef and curry puffs in the ratio 3 : 1. If a customer bought 75% of the lotus paste puffs and all of the curry puffs, what percentage of the beef puffs must Jen sell for her to maintain the original percentage of lotus paste puffs at first? Leave your answer in decimals and correct to 1 decimal place.

Lotus paste puffs	Beef puffs	Curry puffs
2 u	3 u
	2.25 u	0.75 u

	Lotus paste puffs	Beef puffs	Curry puffs	Total puffs
Before	2 u	2.25 u	0.75 u	5 u
Change	- 1.5 u	- 1.5 u	- 0.75 u
After	0.5 u	0.75 u	0	1.25 u

40% = ⁴⁰₁₀₀ = ²₅
75% = ⁷⁵₁₀₀ = ³₄

Total number of puffs = 5 u

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

Number of beef 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 lotus paste puffs sold
= 75% x 2 u
= ⁷⁵₁₀₀ x 2 u
= ³₄ x 2 u
= 1.5 u

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

Number of lotus paste puffs left 
= 2 u - 1.5 u
= 0.5 u

To maintain the percentage of the lotus paste puffs in the end, 
40% → 0.5 u
100% → ^0.5₄₀ x 100 = 1.25 u

Total number of puffs in the end to maintain the original percentage of lotus paste puffs = 1.25 u

Number of beef puffs left
= 1.25 u - 0.5 u
= 0.75 u

Number of beef puffs that Jen must sell to maintain the original percentage of lotus paste puffs
= 2.25 u - 0.75 u
= 1.5 u

Percentage of the beef puffs that Jen must sell
= ^1.5_2.25 x 100%
= 66.7%

Answer(s): 66.7%