Given: The sum of money is Rs. 2000 which becomes Rs. 2420 at 10% per annum Formula used: Amount =p×(1+r/100)n Calculation: Let the time period be t Amount =p×(1+r/100)n ⇒2420=2000×(1+10/100)t ⇒2420/2000=(11/10)t ⇒(121/100)=(11/10)t ⇒(11/10)2=(11/10)t ⇒ t = 2 years ∴ The time is 2 years.