Question

The simple interest on a principal for a period of 5 years is four-fifths of the principal itself. Calculate the rate of interest per annum.​

Answer 1

Answer:

The rate of interest per annum is 16%.

Step-by-step explanation:

Let us consider the principle be P.

The simple interest on a principal for a period of 5 years is four-fifths of the principal itself.

so,

    Simple Interest  $=\frac{4}{5} Principle$

we know that,

simple interest

                                   $\frac{P R T}{100} =\frac{4}{5}P\\ \\ \frac{RT}{100}=\frac{4}{5} \\ \\ 5RT=400\\ \\ RT=80\\ \\ 5R=80\\ \\ R=\frac{80}{5}=16$