A hemispherical tank full of water is emptied by a pipe at the rate of 7.7 litres per second. How much time (in hours) will it take to empty \(\frac{2}{3}\)part of the tank, if the internal radius of the tank is 10.5 m?
1
\(\frac{185}{3}\)
2
\(\frac{175}{3}\)
3
\(\frac{185}{6}\)
4
\(\frac{175}{2}\)