The effort pulley is twice as big as the load pulley. The force therefore on the load pulley is halved to 5kg. The pulley pulls down on the lever with a force of 5kg. The load on the other end of the lever is 3 metres away from the fulcrum while the effort is 1 metre away from the fulcrum. The maximum weight lifted is 5/3 = 1.66 kg.