Min made puffs for sale. 50% of the puffs were kaya puffs and the rest were lotus paste and beef puffs in the ratio 3 : 2. If a customer bought 80% of the kaya puffs and all of the beef puffs, what percentage of the lotus paste puffs must Min sell for her to maintain the original percentage of kaya puffs at first? Leave your answer in decimals and correct to 1 decimal place.

Kaya puffs	Lotus paste puffs	Beef puffs
1 u	1 u
	0.6 u	0.4 u

	Kaya puffs	Lotus paste puffs	Beef puffs	Total puffs
Before	1 u	0.6 u	0.4 u	2 u
Change	- 0.8 u	- 0.4 u	- 0.4 u
After	0.2 u	0.2 u	0	0.4 u

50% = ⁵⁰₁₀₀ = ¹₂
80% = ⁸⁰₁₀₀ = ⁴₅

Total number of puffs = 2 u

Number of lotus paste and beef puffs
= 2 u - 1 u
= 1 u

Number of lotus paste puffs at first
= ³₅ x 1 u
= 0.6 u

Number of beef puffs at first
= 1 u - 0.6 u
= 0.4 u

Number of kaya puffs sold
= 80% x 1 u
= ⁸⁰₁₀₀ x 1 u
= ⁴₅ x 1 u
= 0.8 u

Number of beef puffs sold
= ²₅ x 1 u
= 0.4 u

Number of kaya puffs left 
= 1 u - 0.8 u
= 0.2 u

To maintain the percentage of the kaya puffs in the end, 
50% → 0.2 u
100% → ^0.2₅₀ x 100 = 0.4 u

Total number of puffs in the end to maintain the original percentage of kaya puffs = 0.4 u

Number of lotus paste puffs left
= 0.4 u - 0.2 u
= 0.2 u

Number of lotus paste puffs that Min must sell to maintain the original percentage of kaya puffs
= 0.6 u - 0.2 u
= 0.4 u

Percentage of the lotus paste puffs that Min must sell
= ^0.4_0.6 x 100%
= 66.7%

Answer(s): 66.7%