The compound interest on ₹4,000 at the rate of 5% p.a. is ₹630.50, then the time period is:

3 years

The formula that we used here is :-

Compound interest = Amount - Principal

Compound interest = P$(1 \;+\; \frac{R}{100})^t$ - P

630.50 = 4000 [$(1 \;+\; \frac{5}{100})^t$- 1 ]

\(\frac{1261}{8000}\) =  [ $(1 \;+\; \frac{1}{20})^t$ - 1 ]

\(\frac{1261}{8000}\)  + 1 = ( 1 + \(\frac{1}{20}\) )t 

\(\frac{9261}{8000}\)  = (  \(\frac{21}{100}\) )t

( \(\frac{21}{20}\) )³  =( \(\frac{21}{20}\) )t

So,

t = 3

Hence , time is 3 years.