Question

From the ground floor,a man comes up to the third floor of a building using a staircase. Another person comes up to the same floor,using an elevator. Neglecting friction compare the work in two cases.

Answer 1

The work done is equal to the change in potential energy. The final potential energy is gravitational potential energy  (= mgh). Now, as the height from ground is same, the difference in potential energy will come only due to the difference in mass of the persons. So, the potential energy will be the ratio of the masses of the two persons.