If a 1.0-kg-mass block is on the left cap, how much total mass must be placed on the right cap so that the caps equilibrate at equal height?

The total mass that should be placed in the right cap so that the caps equilibrate at equal height is also 1 kg. if equilibrium should be maintained the force in each side should cancel out, so to balance a 1kg mass, a 1 kg mass should also be place on the opposite direction

d. air pressure decreases as altitude increases.

im guessing the west of station b