Question

The interest earned by A on a certain amount compounded at the rate of 10% per annum the end of two years is Rs. 4,410. Then the total amount that A would have got at the end of
first year, in rupees, is
(1) 25,410
(2) 23,100
(3) 21,000
(4) 24,410

Answer 1

SOLUTION :

Compound Interest (C.I) = Rs 4410

Principal (P) = ?

Rate of Interest (R) = 10% per annum

Time (n) = 2 years

We know that

$\bf C.I = P [(1+\frac{R}{100})^{n}-1]$

⇒ $\bf C.I = P [(1+\frac{R}{100})^{n}-1]$

⇒ $\bf 4410 = P [(1+\frac{10}{100})^{2}-1]$

⇒ $\bf 4410 = P [(1+\frac{1}{10})^{2}-1]$

⇒ $\bf 4410 = P [(\frac{10+1}{10})^{2}-1]$

⇒ $\bf 4410 = P [(\frac{11}{10})^{2}-1]$

⇒ $\bf 4410 = P [\frac{121}{100})-1]$

⇒ $\bf 4410 = P [\frac{121-100}{100}]$

⇒ $\bf 4410 = P [\frac{21}{100}]$

⇒ $\bf 4410 \times \frac{100}{21}=P$

⇒ $\bf 21000 = P$

Principal (P) = Rs 21000

∴ Option (3) 21000 is the correct answer.

Answer 2

Answer:23,100

Explanation: principal=21000:R.I= 10%:

1 year compounded .I= 23,100