Question

Compound interest on a certain sum of money at 5% per annum for two years is Rs. 246. Calculate simple interest on the same sum for 3 years at 6% per annum.

Answer 1

$S.I=\frac{P\times r\times t}{100}A=P(1+\frac{r}{100}{)}^{t}C.I=A-P$

Where,

C. I = Compound interest

S.I = Simple interest

A = Amount

P = Principal

r = rate %

t = time in years

Given, compound interest on a certain sum of money at 5% per annum for 2 years is Rs. 246.

∴ r = 5%

t = 2 years

C.I = Rs. 246

P = ?

A = C.I + P

⇒ A = P + 246

therefore,

$P+246=P(1+\frac{5}{100}{)}^2\Rightarrow P+246=P\times {1.05}^2\Rightarrow 246=1.1025P–P\Rightarrow 246=0.1025P\Rightarrow P=2400$

Now, S.I on the same sum for 3 years at 6% per annum.

∴ r = 6%

t = 3 years

$S.I=\frac{(2400\times 6\times 3)}{100}\Rightarrow S.I=Rs.432$

The simple interest on the same sum for 3 years at 6% per annum is Rs. 432