# In How Many Years Sum will be Rs. 4096? If

After how many years will Rs. 3375 become Rs. 4096 at 20/3% per annum compound interest?

- 4 years
- 2 years
- 2 years
- 3years

**Answer: (4) 3 years**

**Explanation:-
**Let the time is t years.

**Given-**

Principal Rs,3375, Amount = Rs.4096 & Rate = 20/3 %

Then, Compound Interest = 4096 – 3375

= Rs.721

**Formula-**

**Compound Interest = P [(1 + R/100)**

^{t}– 1]**Where, P = principal, R = rate, t = time.**

4096 = 3375(1 + 20/3 x 100)

^{t}

4096 = 3375(1 + 1/15)

^{t}

4096 = 3375(16/15)

^{t}

4096/3375 = (16/15)

^{t}

(16/15)

^{3}= (16/15)

^{t}

Comparing on both side,

t = 3 years

Hence, the answer is (4) 3 years.