With reference to Fig. 7.6 of a cube of edge a and mass m, state whether the following are true or false. (O is the centre of the cube.)

(a) The moment of inertia of cube about z-axis is I_{z} = I_{x} + I_{y}

(b) The moment of inertia of cube about z′ is I'_{z} = I_{z} + (m a^{2})/2

(c) The moment of inertia of cube about z'' is = I_{z} + (m a^{2})/2

(d) I_{x} = I_{y}