An unknown immiscible liquid seeps into the bottom of an open oil tank. some measurements indicate that the depth of the unknown liquid is 1.5 m and the depth of the oil (specific weight ???? 8.5 kn/m

An unknown immiscible liquid seeps into the bottom of an open oil tank. some measurements indicate that the depth of the unknown liquid is 1.5 m and the depth of the oil (specific weight ???? 8.5 kn/m3) floating on top is 5.0 m. a pressure gage connected to the bottom of the tank reads 65 kpa. what is the specific grav- ity of the unknown liquid