Anna made croissants for sale. 55% of the croissants were curry croissants and the rest were egg and sardine croissants in the ratio 2 : 1. If a customer bought 75% of the curry croissants and all of the sardine croissants, what percentage of the egg croissants must Anna sell for her to maintain the original percentage of curry croissants at first? Leave your answer in decimals and correct to 1 decimal place.

Curry croissants	Egg croissants	Sardine croissants
11 u	9 u
	6 u	3 u

	Curry croissants	Egg croissants	Sardine croissants	Total croissants
Before	11 u	6 u	3 u	20 u
Change	- 8.25 u	- 3.75 u	- 3 u
After	2.75 u	2.25 u	0	5 u

55% = ⁵⁵₁₀₀ = ¹¹₂₀
75% = ⁷⁵₁₀₀ = ³₄

Total number of croissants = 20 u

Number of egg and sardine croissants
= 20 u - 11 u
= 9 u

Number of egg croissants at first
= ²₃ x 9 u
= 6 u

Number of sardine croissants at first
= 9 u - 6 u
= 3 u

Number of curry croissants sold
= 75% x 11 u
= ⁷⁵₁₀₀ x 11 u
= ³₄ x 11 u
= 8.25 u

Number of sardine croissants sold
= ¹₃ x 9 u
= 3 u

Number of curry croissants left 
= 11 u - 8.25 u
= 2.75 u

To maintain the percentage of the curry croissants in the end, 
55% → 2.75 u
100% → ^2.75₅₅ x 100 = 5 u

Total number of croissants in the end to maintain the original percentage of curry croissants = 5 u

Number of egg croissants left
= 5 u - 2.75 u
= 2.25 u

Number of egg croissants that Anna must sell to maintain the original percentage of curry croissants
= 6 u - 2.25 u
= 3.75 u

Percentage of the egg croissants that Anna must sell
= ^3.75₆ x 100%
= 62.5%

Answer(s): 62.5%