L + L/2 = 3L/2For the sum of the clockwise torques I understand that 200*L+200(L/2) but I don't understand 200*(3L/2) where did the "3L" come from ?
You can also write that as: (3/2)*L
You can also do this:
200*L + 200*(L/2) = 200*L + 100*L = 300*L
Please convince yourself that these are equivalent.