Potential dividers

A 5.0 V driver cell is connected across a uniform wire XY of length 120 cm. A second circuit has a 3.0 V cell in series with a 150 Ω and a 50 Ω resistor. A galvanometer connects the junction of the two resistors to a sliding contact Z on XY. Both cells have negligible internal resistance. What is the balance length XZ when the galvanometer shows no deflection?