Joelle made muffins for sale. 40% of the muffins were chicken muffins and the rest were kaya and lotus paste muffins in the ratio 4 : 1. If a customer bought 65% of the chicken muffins and all of the lotus paste muffins, what percentage of the kaya muffins must Joelle sell for her to maintain the original percentage of chicken muffins at first? Leave your answer in decimals and correct to 1 decimal place.

Chicken muffins	Kaya muffins	Lotus paste muffins
2 u	3 u
	2.4 u	0.6 u

	Chicken muffins	Kaya muffins	Lotus paste muffins	Total muffins
Before	2 u	2.4 u	0.6 u	5 u
Change	- 1.3 u	- 1.35 u	- 0.6 u
After	0.7 u	1.05 u	0	1.75 u

40% = ⁴⁰₁₀₀ = ²₅
65% = ⁶⁵₁₀₀ = ¹³₂₀

Total number of muffins = 5 u

Number of kaya and lotus paste muffins
= 5 u - 2 u
= 3 u

Number of kaya muffins at first
= ⁴₅ x 3 u
= 2.4 u

Number of lotus paste muffins at first
= 3 u - 2.4 u
= 0.6 u

Number of chicken muffins sold
= 65% x 2 u
= ⁶⁵₁₀₀ x 2 u
= ¹³₂₀ x 2 u
= 1.3 u

Number of lotus paste muffins sold
= ¹₅ x 3 u
= 0.6 u

Number of chicken muffins left 
= 2 u - 1.3 u
= 0.7 u

To maintain the percentage of the chicken muffins in the end, 
40% → 0.7 u
100% → ^0.7₄₀ x 100 = 1.75 u

Total number of muffins in the end to maintain the original percentage of chicken muffins = 1.75 u

Number of kaya muffins left
= 1.75 u - 0.7 u
= 1.05 u

Number of kaya muffins that Joelle must sell to maintain the original percentage of chicken muffins
= 2.4 u - 1.05 u
= 1.35 u

Percentage of the kaya muffins that Joelle must sell
= ^1.35_2.4 x 100%
= 56.3%

Answer(s): 56.3%