A man spend 20% of his monthly salary on his children's education and 50% of his salary on food and transport. After Paying the rent of Rs.1000, he is left with Rs.2000. What is his monthly salary?

Let his monthly salary be 'P'

20% on children's education =  $\frac{20P}{100} = \frac{P}{5}$

50% on food and transport =  $\frac{50P}{100} = \frac{P}{2}$

1000 on rent

=>  $P - \frac{P}{5} - \frac{P}{2} - 1000 = 2000=> 3P = 30000=> P = 10000$

Therefore, his monthly salary = Rs. 10,000