A store owner has 40 more chikoos than starfruits. After he sold 75% of the chikoos and 20% of the starfruits, he is left with 100 more starfruits than chikoos. What fraction of the fruits left were starfruits?

	Chikoos		Starfruits
Comparing chikoos and starfruits at first	40 more
Before	4x5 = 20 u	+ 40	5x4 = 20 u
Change	- 3x5 = - 15 u	- 30	- 1x4 = - 4 u
After	1x5 = 5 u	+ 10	4x4 = 16 u
Comparing chikoos  and starfruits in the end			100 more

75% = ⁷⁵₁₀₀ = ³₄ 
75% x 40 = ³₄ x 40 = 30
40 - 30 = 10

20% = ²⁰₁₀₀ = ¹₅ 

The number of starfruits is 100 more than the number of chikoos in the end. So, if another 100 chikoos are added, the number of chikoos and starfruits in the end will be the same.

5 u + 10 + 100 = 16 u
5 u + 110 = 16 u
16 u - 5 u = 110
11 u = 110

1 u = 110 ÷ 11 = 10

Number of starfruits left
= 16 u
= 16 x 10
= 160

Total number of fruits left
= 5 u + 10 + 16 u
= 21 u + 10
= 21 x 10 + 10
= 210 + 10
= 220

^{Starfruits left}_{Total fruits left} = ¹⁶⁰₂₂₀ = ⁸₁₁

Answer(s): ⁸₁₁