Question

if Sagar earns rupees 16000 per month he spend 1 upon 4 of his income on food 3 upon 10 of the remainder on house rent and 5upon21 of the remainder on the education of children how much money is still left with him

Answer 1

Spent on food = (1/4)*16000= 4000
Remaining = 12000
Spent on rent = (3/10)*12000=3600.

Now pick your lazy a** up and pick the pen, solve the rest on your own.