Newton's laws of motion — practice question

Particle $A$, with mass $1.6\,\text{kg}$, is at rest on a horizontal table and is linked to one end of a light inextensible string. This string runs over a small smooth pulley $P$ at the table’s edge. The free end is connected to particle $B$, of mass $2.4\,\text{kg}$, which hangs vertically beneath the pulley. The system is let go from rest, with the string taut and $B$ positioned $0.5\,\text{m}$ above the ground, as the diagram shows. During the resulting motion, $A$ does not reach $P$ before $B$ hits the ground.