The volume of the hemisphere is calculated through the equation,
V(hemisphere) = 2πr³/3
and that of the cylinder is
V(cylinder) = πr²h
Substituting the given dimensions in the figure shown,
2 x V(hemisphere) = 2 x (2)(π)(6 in)³ /3 = 288π in³
V(cylinder) = (π)(6 in)²(10 in) = 360π in³
Adding up the volumes of the three solids,
total volume = 288π in³ + 360π in³ = 648π in³
Thus, the answer is letter D.