Three persons A, B and C donate 10%, 7% and 9% respectively of their monthly salaries to a charitable trust. Monthly salaries of A and B are equal and the difference between the donations of A and B is ₹900. If the total donation by A and B is ₹600 more than that of C, then what is the monthly salary (in ₹) of C?

Monthly salaries of A and B are equal.

Let the monthly salaries of A and B are 'p'.

The difference between the donations of A and B is ₹900.

$$\frac{10}{100}p-\frac{7}{100}p=900$$

$$\frac{3}{100}p=900$$

p = 30000

The monthly salaries of A and B are ₹30000.

The total donation by A and B is ₹600 more than that of C.

$$\frac{10}{100}\times30000+\frac{7}{100}\times30000$$ = Donation by C + 600

$$\frac{17}{100}\times30000$$ = Donation by C + 600

5100 = Donation by C + 600

Donation by C = ₹4500

Let the monthly salary of C = t

$$\frac{9}{100}\times t=4500$$

t = 50000

Monthly salary of C = ₹50000

Hence, the correct answer is Option C