Rachel made croissants for sale. 40% of the croissants were curry croissants and the rest were sardine and egg croissants in the ratio 3 : 2. If a customer bought 60% of the curry croissants and all of the egg croissants, what percentage of the sardine croissants must Rachel 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	Sardine croissants	Egg croissants
2 u	3 u
	1.8 u	1.2 u

	Curry croissants	Sardine croissants	Egg croissants	Total croissants
Before	2 u	1.8 u	1.2 u	5 u
Change	- 1.2 u	- 0.6 u	- 1.2 u
After	0.8 u	1.2 u	0	2 u

40% = ⁴⁰₁₀₀ = ²₅
60% = ⁶⁰₁₀₀ = ³₅

Total number of croissants = 5 u

Number of sardine and egg croissants
= 5 u - 2 u
= 3 u

Number of sardine croissants at first
= ³₅ x 3 u
= 1.8 u

Number of egg croissants at first
= 3 u - 1.8 u
= 1.2 u

Number of curry croissants sold
= 60% x 2 u
= ⁶⁰₁₀₀ x 2 u
= ³₅ x 2 u
= 1.2 u

Number of egg croissants sold
= ²₅ x 3 u
= 1.2 u

Number of curry croissants left 
= 2 u - 1.2 u
= 0.8 u

To maintain the percentage of the curry croissants in the end, 
40% → 0.8 u
100% → ^0.8₄₀ x 100 = 2 u

Total number of croissants in the end to maintain the original percentage of curry croissants = 2 u

Number of sardine croissants left
= 2 u - 0.8 u
= 1.2 u

Number of sardine croissants that Rachel must sell to maintain the original percentage of curry croissants
= 1.8 u - 1.2 u
= 0.6 u

Percentage of the sardine croissants that Rachel must sell
= ^0.6_1.8 x 100%
= 33.3%

Answer(s): 33.3%