A loaded beam ABCDE is simply supported at B and D and carries point loads of 40 kN, 80 kN, and 60 kN at A, C, and E respectively, together with a uniformly distributed load of 20 kN/m between B and D. AB = DE = 1 m, and BC = CD = 4 m. Find the dimensions of a suitable W – Shape beam to restrict the maximum bending stress in the beam to 140 N/mm2. Ignore the mass of the beam itself.