Question

A man of mass 60 kg is standing on a floor holding a stine weighing 40 N. What is the force with which the floor is pushing him up?

Answer 1

Total force exerted by the man on floor
=mg+40 N
=60×10 + 40
=600+40
=640N

With the help of Newton's 3rd law: Every action has an equal and opposite reaction

Floor will also apply the same force in opposite direction.