Monthly salaries of Pia and Som are in the respective ratio of 5: 4. Pia, from her monthly salary, gives $$\frac{3}{5}$$th to her mother. 15% towards her sister’s tuition fees, 18% towards a loan and she shops with the remaining amount which was Rs. 2,100. What is the monthly salary of Som ?

Let monthly salary of Pia = $$Rs. 500x$$

=> Monthly salary of Som = $$Rs. 400x$$

Amount given by Pia to her mother = $$\frac{3}{5} \times 500x = 300x$$

Amount for her sister tuition fees = $$\frac{15}{100} \times 500x = 75x$$

Amount for loan = $$\frac{18}{100} \times 500x = 90x$$

=> Amount left = $$500x - (300x + 75x + 90x) = 2100$$

=> $$500x - 465x = 35x = 2100$$

=> $$x = \frac{2100}{35} = 60$$

$$\therefore$$ Som's salary = $$400 \times 60 = Rs. 24,000$$