A hemispherical tank fill 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 rank is 10.5 m?

• A. \(\frac{185}{3}\)
• B. \(\frac{175}{3}\)
• C. \(\frac{185}{6}\)
• D. \(\frac{175}{2}\)