Olivia made croissants for sale. 60% of the croissants were egg croissants and the rest were chocolate and lotus paste croissants in the ratio 3 : 2. If a customer bought 65% of the egg croissants and all of the lotus paste croissants, what percentage of the chocolate croissants must Olivia 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	Chocolate croissants	Lotus paste croissants
3 u	2 u
	1.2 u	0.8 u

	Egg croissants	Chocolate croissants	Lotus paste croissants	Total croissants
Before	3 u	1.2 u	0.8 u	5 u
Change	- 1.95 u	- 0.5 u	- 0.8 u
After	1.05 u	0.7 u	0	1.75 u

60% = ⁶⁰₁₀₀ = ³₅
65% = ⁶⁵₁₀₀ = ¹³₂₀

Total number of croissants = 5 u

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

Number of chocolate croissants at first
= ³₅ x 2 u
= 1.2 u

Number of lotus paste croissants at first
= 2 u - 1.2 u
= 0.8 u

Number of egg croissants sold
= 65% x 3 u
= ⁶⁵₁₀₀ x 3 u
= ¹³₂₀ x 3 u
= 1.95 u

Number of lotus paste croissants sold
= ²₅ x 2 u
= 0.8 u

Number of egg croissants left 
= 3 u - 1.95 u
= 1.05 u

To maintain the percentage of the egg croissants in the end, 
60% → 1.05 u
100% → ^1.05₆₀ x 100 = 1.75 u

Total number of croissants in the end to maintain the original percentage of egg croissants = 1.75 u

Number of chocolate croissants left
= 1.75 u - 1.05 u
= 0.7 u

Number of chocolate croissants that Olivia must sell to maintain the original percentage of egg croissants
= 1.2 u - 0.7 u
= 0.5 u

Percentage of the chocolate croissants that Olivia must sell
= ^0.5_1.2 x 100%
= 41.7%

Answer(s): 41.7%