A fruit stall owner had some pears, apples and oranges. For every 2 pears, there were 3 apples. For every 9 apples, there were 5 oranges. 36 pears were rotten and thrown away. Then 1/5 of the remaining fruits were pears.

Question

A fruit stall owner had some pears, apples and oranges. For every 2 pears, there were 3 apples. For every 9 apples, there were 5 oranges. 36 pears were rotten and thrown away. Then 1/5 of the remaining fruits were pears. 
How many fruits did the fruit owner have at first?

mathhelper · Answer

pears : apples = 2 : 3 = 6 : 9 , ( I wanted the same number for apples)
apples : oranges = 9 : 5

so
pears : apples : oranges = 6 : 9 : 5 or 6x : 9x : 5x
for a total of 20x fruits

36 bad pears, so pears left = 6x-36
total remaining = 20x - 36

"Then 1/5 of the remaining fruits were pears"
----> (1/5)(20x - 36) = 6x - 36
20x - 36 = 30x - 180
-10x = -144
oops, x has to be a whole number
I can't find any error in my solution, perhaps you can spot one