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?

50000

10% = \(\frac{1}{10}\) , 7% = \(\frac{7}{100}\) , 9% = \(\frac{9}{100}\)

Let Salary of A = Salary of B = 100a , salary of C = 100b

Donated amount of   A = 100a × \(\frac{1}{10}\)  = 10a

Donated amount of  B = (100a × \(\frac{7}{100}\)  = 7a

Donated amount of  C = 100b × \(\frac{9}{100}\) = 9b

ATQ,

3a = 900

a = 300

Total donation of A and B =  17a

 17 × 300 = 5100

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

 5100 – 9b = 600

 b = 500

Monthly salary of C = 100b = 100 × 500

 Rs. 50000