Vanessa made puffs for sale. 40% of the puffs were beef puffs and the rest were curry and egg puffs in the ratio 2 : 1. If a customer bought 85% of the beef puffs and all of the egg puffs, what percentage of the curry puffs must Vanessa sell for her to maintain the original percentage of beef puffs at first? Leave your answer in decimals and correct to 1 decimal place.

Beef puffs	Curry puffs	Egg puffs
2 u	3 u
	2 u	1 u

	Beef puffs	Curry puffs	Egg puffs	Total puffs
Before	2 u	2 u	1 u	5 u
Change	- 1.7 u	- 1.55 u	- 1 u
After	0.3 u	0.45 u	0	0.75 u

40% = ⁴⁰₁₀₀ = ²₅
85% = ⁸⁵₁₀₀ = ¹⁷₂₀

Total number of puffs = 5 u

Number of curry and egg puffs
= 5 u - 2 u
= 3 u

Number of curry puffs at first
= ²₃ x 3 u
= 2 u

Number of egg puffs at first
= 3 u - 2 u
= 1 u

Number of beef puffs sold
= 85% x 2 u
= ⁸⁵₁₀₀ x 2 u
= ¹⁷₂₀ x 2 u
= 1.7 u

Number of egg puffs sold
= ¹₃ x 3 u
= 1 u

Number of beef puffs left 
= 2 u - 1.7 u
= 0.3 u

To maintain the percentage of the beef puffs in the end, 
40% → 0.3 u
100% → ^0.3₄₀ x 100 = 0.75 u

Total number of puffs in the end to maintain the original percentage of beef puffs = 0.75 u

Number of curry puffs left
= 0.75 u - 0.3 u
= 0.45 u

Number of curry puffs that Vanessa must sell to maintain the original percentage of beef puffs
= 2 u - 0.45 u
= 1.55 u

Percentage of the curry puffs that Vanessa must sell
= ^1.55₂ x 100%
= 77.5%

Answer(s): 77.5%