In one minute, \(\frac{1}{16}\) - \(\frac{1}{8}\) = - \(\frac{1}{16}\) of the tank can be filled, i.e.,\(\frac{1}{16}\) of the whole tank can be emptied.
\(\therefore\) The whole tank can be emptied in 16 minutes.
Since the tank is half full, therefore it will be emptied in 8 minutes.