Identify the pair whose dimensions are equal

A lift is moving down with acceleration $$a.$$ A man in the lift drops a ball inside the lift. The acceleration of the ball as observed by the man in the lift and a man standing stationary on the ground are respectively

From a building two balls A and B are thrown such that A is thrown upwards and B downwards ( both vertically with the same speed ). If v_A and v_B are their respective velocities on reaching the ground, then

A light string passing over a smooth light pulley connects two blocks of masses $${m_1}$$ and $${m_2}$$ (vertically). If the acceleration of the system is $$g/8$$, then the ratio of the masses is