Pamela made croissants for sale. 50% of the croissants were egg croissants and the rest were curry and mushroom croissants in the ratio 3 : 1. If a customer bought 75% of the egg croissants and all of the mushroom croissants, what percentage of the curry croissants must Pamela sell for her to maintain the original percentage of egg croissants at first? Leave your answer in decimals and correct to 1 decimal place.

Egg croissants	Curry croissants	Mushroom croissants
1 u	1 u
	0.75 u	0.25 u

	Egg croissants	Curry croissants	Mushroom croissants	Total croissants
Before	1 u	0.75 u	0.25 u	2 u
Change	- 0.75 u	- 0.5 u	- 0.25 u
After	0.25 u	0.25 u	0	0.5 u

50% = ⁵⁰₁₀₀ = ¹₂
75% = ⁷⁵₁₀₀ = ³₄

Total number of croissants = 2 u

Number of curry and mushroom croissants
= 2 u - 1 u
= 1 u

Number of curry croissants at first
= ³₄ x 1 u
= 0.75 u

Number of mushroom croissants at first
= 1 u - 0.75 u
= 0.25 u

Number of egg croissants sold
= 75% x 1 u
= ⁷⁵₁₀₀ x 1 u
= ³₄ x 1 u
= 0.75 u

Number of mushroom croissants sold
= ¹₄ x 1 u
= 0.25 u

Number of egg croissants left 
= 1 u - 0.75 u
= 0.25 u

To maintain the percentage of the egg croissants in the end, 
50% → 0.25 u
100% → ^0.25₅₀ x 100 = 0.5 u

Total number of croissants in the end to maintain the original percentage of egg croissants = 0.5 u

Number of curry croissants left
= 0.5 u - 0.25 u
= 0.25 u

Number of curry croissants that Pamela must sell to maintain the original percentage of egg croissants
= 0.75 u - 0.25 u
= 0.5 u

Percentage of the curry croissants that Pamela must sell
= ^0.5_0.75 x 100%
= 66.7%

Answer(s): 66.7%