In what time will Rs.1000 become Rs.1331 at 10% per annum compounded annually?

Principal = Rs. 1000;
Amount = Rs. 1331;
Rate = 10% p.a.
Let the time be n years.
Then, [ 1000 (1+ (10/100))^n ] = 1331 or (11/10)^n = (1331/1000) = (11/10)^3
n = 3 years