The difference between compound interest and simple interest on a certain sum for 2 years at 12% per annum is 36 Taka. What is the principal amount?

Question: The difference between compound interest and simple interest on a certain sum for 2 years at 12% per annum is 36 Taka. What is the principal amount?

Solution:
For 2 years, the difference between compound interest (CI) and simple interest (SI) is given by:

Difference = P × (r/100)^t
where,
P = Principal amount
r = interest rate = 12%
Time = t = 2 years
Difference = 36 Taka

So, we get,
36 = P × (12/100)²
36 = P × (144/10000)
∴ P = 2500 Taka