Question

THE WATTAGE OF AN APPLIANCE INDICATES THE AVERAGE POWER CONSUMPTION IN WATTS(W),WHERE 1W =1J/S WHAT IS THE DIFFERENCE IN THE NUMBER OF KJ OF ENERGY CONSUMED PER MONTH BETWEEN A REFFIGERATION UNIT THAT CONSUMES 625 W AND ONE THAT CONSUMES 855W? IF ELECTRICITY COSTS $0.15 OER KWH WHAT IS THE MONTHLY COST DIFFERENCE TO OPERATE THE TWO REFRIGERATORS? (ASSUME 30.0 DAYS IN ONE MONTH AND 24.0 HOURS PER DAY.