Question

at what rate percent per annum compound interest will rupees 12000 amounts to rupees 15972 in 3 years ​

Answer 1

Answer:

The rate of percentage per annum at compound interest is 8.9%

Step-by-step explanation:

Given as :

Principal = p = Rs 12,000

Amount = A = Rs 15972

Time  = t = 3 years

Let The rate of interest = r%

From compound interest

Amount = principal × $(1+\dfrac{rate}{100})^{time}$

or, A = p × $(1+\dfrac{r}{100})^{t}$

or, Rs 15972 = Rs 12,000 × $(1+\dfrac{r}{100})^{3}$

Or, $(1+\dfrac{r}{100})^{3}$ = $\dfrac{15972}{12000}$

or, $(1+\dfrac{r}{100})^{3}$ = 1.331

Taking power $\dfrac{1}{3}$ both side

1 + $\dfrac{r}{100}$ = $1.331^{\frac{1}{3}}$

or, $\dfrac{r}{100}$ = 1.089 - 1

∴  r = 8.9

So, Rate of interest = r = 8.9%

Hence, The rate of percentage per annum at compound interest is 8.9% Answer