Subject: mathqa
Question: rohan spends 40 % of his salary on food , 20 % on house rent , 10 % on entertainment and 10 % on conveyance . if his savings at the end of a month are rs . 3000 . then his monthly salary is
Option: 
A: rs . 3000
B: rs . 12000
C: rs . 15000
D: rs . 9000
Answer: C