A coil removes 60 grains of moisture per pound of dry air entering at 80 degrees dry bulb and 50% relative humidity. If the leaving air dry bulb temperature is 54 degrees, what is the leaving dew point temperature?

A coil removes 60 grains of moisture per pound of dry air entering at 80 degrees dry bulb and 50% relative humidity. If the leaving air dry bulb temperature is 54 degrees, what is the leaving dew point temperature?