A torque of $\mathrm{T}=10 \mathrm{kN}-\mathrm{m}$ is transmitted between two flanged shafts by means of four $22-\mathrm{mm}$-diameter bolts. Determine the average shear stress in each bolt if the diameter of the bolt circle is $250 \mathrm{mm}$. (Disregard friction between the flanges.)