Question

A sum of money lent at compound interest amounts to Rs. 3025 in two years and to
Rs. 3660.25 in 4 years. Find the rate of interest.​

Answer 1

Answer:

Rate of interest is 21 %

Step-by-step explanation:

P = ₹3025

A = ₹3660.25

T = 4 years

A = P ( 1 + R / 100 )

3660.25 = 3025 ( 1 + R / 100 )

366025 / 3025 = 1 + R / 100

1.21 = 1 + R / 100

1.21 - 1 = R / 100

0.21 = R / 100

0.21 * 100 = R

21 = R

Answer 2

Answer:

The rate of interest is 10%

Step-by-step explanation:

Amount for a principle P compounded annually for n years at rate R per annum is given by,

A= P $(1+\frac{R}{100})^{n}$

Amount for 2 years = A₂ = 3025 --------(1)

Amount for 4 years = $A_{4}$ = 3660.25 ------(2)

Dividing Equation (2) by (1),

$\frac{A₄}{A₂} = \frac{3660.25}{3025}$=  $(1+\frac{R}{100})^{2}$

On simplifying,

$(\frac{11}{10}) ^{2}$ = $(1+\frac{R}{100})^{2}$

On solving for R,

R= 10 %

The correct answer is 10%.