Summary
In this particular application, we see:
a. The force necessary to lift the weight is equal to the weight. Therefore there is no advantage (the pulley did not multiply the applied force).
b. By applying a downward force, we were able to lift a weight upward. Therefore the pulley changes the direction of the force necessary to lift the weight. (If we had not used the pulley, we’d need an upward force to lift the weight).
c. To lift the weight by one foot we have to pull the rope down by one foot.