A store owner has 80 less mangosteens than chikoos. After he sold 80% of the mangosteens and 35% of the chikoos, he is left with 38 less mangosteens than chikoos. What fraction of the fruits left were mangosteens?

	Mangosteens		Chikoos
Comparing mangosteens and chikoos at first			80 less
Before	5x4 = 20 u	+ 80	20x1 = 20 u
Change	- 4x4 = - 16 u	- 64	- 7x1 = - 7 u
After	1x4 = 4 u	+ 16	13x1 = 13 u
Comparing mangosteens  and chikoos in the end	38 less

80% = ⁸⁰₁₀₀ = ⁴₅ 
80% x 80 = ⁴₅ x 80 = 64
80 - 64 = 16

35% = ³⁵₁₀₀ = ⁷₂₀ 

The number of mangosteens is 38 less than the number of chikoos in the end. So, if another 38 mangosteens are added, the number of mangosteens and chikoos in the end will be the same.

4 u + 16 + 38 = 13 u
4 u + 54 = 13 u
13 u - 4 u = 54
9 u = 54

1 u = 54 ÷ 9 = 6

Number of mangosteens left
= 4 u + 16
= 4 x 6 + 16
= 24 + 16
= 40

Total number of fruits left
= 4 u + 16 + 13 u
= 17 u + 16
= 17 x 6 + 16
= 102 + 16
= 118

^{Mangosteens left}_{Total fruits left} = ⁴⁰₁₁₈ = ²⁰₅₉

Answer(s): ²⁰₅₉