Winnie made croissants for sale. 40% of the croissants were beef croissants and the rest were lotus paste and chocolate croissants in the ratio 2 : 1. If a customer bought 75% of the beef croissants and all of the chocolate croissants, what percentage of the lotus paste croissants must Winnie sell for her to maintain the original percentage of beef croissants at first? Leave your answer in decimals and correct to 1 decimal place.

Beef croissants	Lotus paste croissants	Chocolate croissants
2 u	3 u
	2 u	1 u

	Beef croissants	Lotus paste croissants	Chocolate croissants	Total croissants
Before	2 u	2 u	1 u	5 u
Change	- 1.5 u	- 1.25 u	- 1 u
After	0.5 u	0.75 u	0	1.25 u

40% = ⁴⁰₁₀₀ = ²₅
75% = ⁷⁵₁₀₀ = ³₄

Total number of croissants = 5 u

Number of lotus paste and chocolate croissants
= 5 u - 2 u
= 3 u

Number of lotus paste croissants at first
= ²₃ x 3 u
= 2 u

Number of chocolate croissants at first
= 3 u - 2 u
= 1 u

Number of beef croissants sold
= 75% x 2 u
= ⁷⁵₁₀₀ x 2 u
= ³₄ x 2 u
= 1.5 u

Number of chocolate croissants sold
= ¹₃ x 3 u
= 1 u

Number of beef croissants left 
= 2 u - 1.5 u
= 0.5 u

To maintain the percentage of the beef croissants in the end, 
40% → 0.5 u
100% → ^0.5₄₀ x 100 = 1.25 u

Total number of croissants in the end to maintain the original percentage of beef croissants = 1.25 u

Number of lotus paste croissants left
= 1.25 u - 0.5 u
= 0.75 u

Number of lotus paste croissants that Winnie must sell to maintain the original percentage of beef croissants
= 2 u - 0.75 u
= 1.25 u

Percentage of the lotus paste croissants that Winnie must sell
= ^1.25₂ x 100%
= 62.5%

Answer(s): 62.5%