Question

a sum of money becomes 8/5 of itself in 5 years a in at a certain rate of simple interest. find the rate of interest​

Answer 1

Answer:

Hello,

Let the principle be rs x

Time is given as 5 years.

So, amount becomes 8x/5

Now ,

We know that

Si = amount - p

SI =8x/5 - x = 3x/5

Now we also know that

si = \frac{p \times r \times t}{100}si=

100

p×r×t

So as per given values.

\begin{gathered} \frac{x \times r \times 5}{100} = \frac{3x}{5} \\ 5x \times r = \frac{3x \times 100}{5} = 60x \\ r = \frac{60x}{5x} = 12\%\end{gathered}

100

x×r×5

=

5

3x

5x×r=

5

3x×100

=60x

r=

5x

60x

=12%