A sum invested at 5% simple interest per annum grows to Rs. 504 in 4 years.…

To solve this, we first find the principal sum from the first scenario and then use that same principal to find the final amount in the second scenario.

1. Find the Principal (P) from the first scenario:

   • Amount (A) = 504

   • Rate (R) = 5%

   • Time (T) = 4 years

   • Formula: A = P * (1 + (R * T) / 100)

   • 504 = P * (1 + (5 * 4) / 100)

   • 504 = P * (1 + 20 / 100)

   • 504 = P * (1 + 0.2)

   • 504 = P * 1.2

   • P = 504 / 1.2 = 420.

2. Calculate the new Amount (A') for the second scenario:

   • Principal (P) = 420

   • New Rate (R') = 10%

   • New Time (T') = 2 1/2 years = 2.5 years

   • Formula: A' = P + (P * R' * T') / 100

   • Interest = (420 * 10 * 2.5) / 100

   • Interest = (420 * 25) / 100 = 105

   • Amount (A') = 420 + 105 = 525.