A closed cylindrical tank filled with water has a hemispherical dome and is connected to an inverted piping system. The liquid in the top part of the piping system has a specific gravity of 0.68, and the remaining parts of the system are filled with water. If the pressure gage reading at A is 90 kPa, determine (a) the pressure in pipe B and (b) the pressure head, in millimeters of mercury, at the top of the dome (point C).