Question

The difference between CI and SI on an amount of rs 15625 for 2 years is rs 625 what is the rate of interest per annum

Answer 1

Answer:

20%

Step-by-step explanation:

CI-SI=(PR^2)÷100^2

625=(15625×R^2)÷(100^2)

R^2 =(6250000)÷(15625)

R^2 =400

R =√400

R = 20

Answer 2

Answer:

The rate of interest per annum = 20 %

Step-by-step explanation:

As per the questions,

The formula for compound interest = $P\times \left ( 1+r \right )^{t} \ - P$

The formula for simple interest = $\frac{P\times r\times t}{100}$

where,

P = principal amount

r = rate of interest

t = time interval

Now,

From the given data of the question we have,

Principle amount (P) = 15625

Time period (t) = 2 years

CI - SI = 625

∴ $P\times \left ( 1+r \right )^{t}-P-\frac{P\times R\times t}{100} = 625$

∴ $P\times \left ( 1+r \right )^{2}-P-\frac{15625\times R\times 2}{100} = 625$

  $P\times (\frac{r}{100} )^{2}=625$

   $15625\times (\frac{r}{100} )^{2}=625$

∴ r = 20 %

Hence, the rate of interest per annum = 20 %