Usha made buns for sale. 50% of the buns were mushroom buns and the rest were lotus paste and curry buns in the ratio 3 : 2. If a customer bought 60% of the mushroom buns and all of the curry buns, what percentage of the lotus paste buns must Usha sell for her to maintain the original percentage of mushroom buns at first? Leave your answer in decimals and correct to 1 decimal place.

Mushroom buns	Lotus paste buns	Curry buns
1 u	1 u
	0.6 u	0.4 u

	Mushroom buns	Lotus paste buns	Curry buns	Total buns
Before	1 u	0.6 u	0.4 u	2 u
Change	- 0.6 u	- 0.2 u	- 0.4 u
After	0.4 u	0.4 u	0	0.8 u

50% = ⁵⁰₁₀₀ = ¹₂
60% = ⁶⁰₁₀₀ = ³₅

Total number of buns = 2 u

Number of lotus paste and curry buns
= 2 u - 1 u
= 1 u

Number of lotus paste buns at first
= ³₅ x 1 u
= 0.6 u

Number of curry buns at first
= 1 u - 0.6 u
= 0.4 u

Number of mushroom buns sold
= 60% x 1 u
= ⁶⁰₁₀₀ x 1 u
= ³₅ x 1 u
= 0.6 u

Number of curry buns sold
= ²₅ x 1 u
= 0.4 u

Number of mushroom buns left 
= 1 u - 0.6 u
= 0.4 u

To maintain the percentage of the mushroom buns in the end, 
50% → 0.4 u
100% → ^0.4₅₀ x 100 = 0.8 u

Total number of buns in the end to maintain the original percentage of mushroom buns = 0.8 u

Number of lotus paste buns left
= 0.8 u - 0.4 u
= 0.4 u

Number of lotus paste buns that Usha must sell to maintain the original percentage of mushroom buns
= 0.6 u - 0.4 u
= 0.2 u

Percentage of the lotus paste buns that Usha must sell
= ^0.2_0.6 x 100%
= 33.3%

Answer(s): 33.3%