Question

The difference between the compound interest and simple interest on a certain sum for 2 years at 7.5% per annum is Rs. 360. Find the sum.

Answer 1

Given, 

C.I – S.I = Rs.360 

Time = 2 years 

Rate = 7.5 % per annum 

Let principal = Rs. P 

So,

\(={P}[({1}+\frac{7.5}{100})^2-{1}]-\frac{P \times 7.5 \times 2}{100}\) = 360

\(={P}\times\frac{249}{1600}-\frac{3P}{20}\) = 360

\(=\frac{249P-240P}{1600}\) = 360

\(={9P}={360\times1600}\)

\(={P}=\frac{360\times1600}{9}\)= Rs 64000

Hence, 

Principal = Rs. 64000