Gabby made croissants for sale. 55% of the croissants were kaya croissants and the rest were beef and chocolate croissants in the ratio 3 : 1. If a customer bought 65% of the kaya croissants and all of the chocolate croissants, what percentage of the beef croissants must Gabby sell for her to maintain the original percentage of kaya croissants at first? Leave your answer in decimals and correct to 1 decimal place.

Kaya croissants	Beef croissants	Chocolate croissants
11 u	9 u
	6.75 u	2.25 u

	Kaya croissants	Beef croissants	Chocolate croissants	Total croissants
Before	11 u	6.75 u	2.25 u	20 u
Change	- 7.15 u	- 3.6 u	- 2.25 u
After	3.85 u	3.15 u	0	7 u

55% = ⁵⁵₁₀₀ = ¹¹₂₀
65% = ⁶⁵₁₀₀ = ¹³₂₀

Total number of croissants = 20 u

Number of beef and chocolate croissants
= 20 u - 11 u
= 9 u

Number of beef croissants at first
= ³₄ x 9 u
= 6.75 u

Number of chocolate croissants at first
= 9 u - 6.75 u
= 2.25 u

Number of kaya croissants sold
= 65% x 11 u
= ⁶⁵₁₀₀ x 11 u
= ¹³₂₀ x 11 u
= 7.15 u

Number of chocolate croissants sold
= ¹₄ x 9 u
= 2.25 u

Number of kaya croissants left 
= 11 u - 7.15 u
= 3.85 u

To maintain the percentage of the kaya croissants in the end, 
55% → 3.85 u
100% → ^3.85₅₅ x 100 = 7 u

Total number of croissants in the end to maintain the original percentage of kaya croissants = 7 u

Number of beef croissants left
= 7 u - 3.85 u
= 3.15 u

Number of beef croissants that Gabby must sell to maintain the original percentage of kaya croissants
= 6.75 u - 3.15 u
= 3.6 u

Percentage of the beef croissants that Gabby must sell
= ^3.6_6.75 x 100%
= 53.3%

Answer(s): 53.3%