A store owner has 85 more passion fruits than starfruits. After he sold 80% of the passion fruits and 10% of the starfruits, he is left with 18 more starfruits than passion fruits. What fraction of the fruits left were starfruits?

	Passion fruits		Starfruits
Comparing passion fruits and starfruits at first	85 more
Before	5x2 = 10 u	+ 85	10x1 = 10 u
Change	- 4x2 = - 8 u	- 68	- 1x1 = - 1 u
After	1x2 = 2 u	+ 17	9x1 = 9 u
Comparing passion fruits  and starfruits in the end			18 more

80% = ⁸⁰₁₀₀ = ⁴₅ 
80% x 85 = ⁴₅ x 85 = 68
85 - 68 = 17

10% = ¹⁰₁₀₀ = ¹₁₀ 

The number of starfruits is 18 more than the number of passion fruits in the end. So, if another 18 passion fruits are added, the number of passion fruits and starfruits in the end will be the same.

2 u + 17 + 18 = 9 u
2 u + 35 = 9 u
9 u - 2 u = 35
7 u = 35

1 u = 35 ÷ 7 = 5

Number of starfruits left
= 9 u
= 9 x 5
= 45

Total number of fruits left
= 2 u + 17 + 9 u
= 11 u + 17
= 11 x 5 + 17
= 55 + 17
= 72

^{Starfruits left}_{Total fruits left} = ⁴⁵₇₂ = ⁵₈

Answer(s): ⁵₈