In how many years will a sum of Rs.800 at 10% per annum compounded semi annually become Rs.926.10

Let the time be 'n' years, Then

$800\times 1+\frac{5}{100}2n=926.10 <=> 1+\frac{5}{100}2n=\frac{9261}{8000}<=>\frac{21}{20}2n=\frac{21}{10}3$

n = 3/2 or n= 1 $\frac{1}{2}$ Years