Question

2.
If a certain sum of money of Rs. 102400
amounts to Rs. 145800 in 3 years. Find the
rate of compound interest.​

Answer 1

Answer:

P=Rs. 102400

n=3 years

CI rate=?

A=P(1+ r/100) ^n

Rs. 145800=Rs. 102400(1+ r/100)^3

145800/102400=(1+r/100) ^3

729/512=(1+ r/100) ^3

(9/8)^3=(1+r/100) ^3

9/8=(1+r/100).......[powers cancelled]

r/100=9/8-1

=1/8

r=1/8 ×100=100/8

=12.5℅

Answer 2

The rate of compound interest is 12.5%.

Step-by-step explanation:

Given : If a certain sum of money of Rs. 102400  amounts to Rs. 145800 in 3 years.

To find : The  rate of compound interest. ?

Solution :

Applying compound interest formula,

$A=P(1+\frac{r}{100})^t$

Where, Principal is P=Rs.102400

Amount is A=Rs.145800

Time is t=3 years

Rate of interest is r

Substitute the value,

$145800=102400(1+\frac{r}{100})^3$

$\frac{145800}{102400}=(1+\frac{r}{100})^3$

$1.423828125=(1+\frac{r}{100})^3$

Taking cube root both side,

$\sqrt[3]{1.423828125}=\sqrt[n]{(1+\frac{r}{100})^3}$

$1.125=1+\frac{r}{100}$

$\frac{r}{100}=1.125-1$

$\frac{r}{100}=0.125$

$r=0.125\times 100$

$r=12.5\%$

Therefore, the rate of compound interest is 12.5%.

#Learn more

Find the compound interest on 15625 at 16% per annum for 9 months compounded quarterly​

https://brainly.in/question/11596124