₹ 500 was invested at 12% per annum simple interest and a certain sum of money at 10% per annum simple interest. If the sum of the interests on both the sum after 4 years is ₹ 480, the other sum of money is:

Given, One of the principal = Rs.500
Rate of interest = 12%
Time period = 4 years
Simple Interest = $$\dfrac{500\times12\times4}{100} = Rs.240$$
Let the other principal be Rs.x
Rate of interest = 10%
Time period = 4 years
Simple Interest = $$\dfrac{x \times 10 \times 4}{100} = Rs.\dfrac{2x}{5}$$

Given. $$240 + \dfrac{2x}{5} = 480$$

=> 1200+2x = 2400
=> 2x = 1200
=> x = 600
Therefore, The other principal = Rs.600.