Question

rohit donated 1/5 of his monthly income to an NGO working for the education of old women,1/4 of his salary spent on food ,1/3on rent and 1/15on other expenses .If he is left with rupees 9000 find his monthly income

Answer 1

Let total amount be x 
Money spent on:
Food = 14x
Rent = 13x
Other expenses = 115x
NGO = 15x
Income - Total amount spent = Remaining amount (9000)
x - (14x+13x+115x+15x) = 9000

x−1720x = 9000

320x = 9000

x=9000⋅203
= 60000