A microwave can reheat 1 cup of coffee in 30 seconds. It takes a coffee-maker 10 minutes to brew 12 cups of coffee. If the coffee-maker requires 900 watts of power and the microwave requires 1200 watt?

The microwave requires more power (1200 watts) than the coffee-maker (900 watts). The microwave reheats coffee quickly in 30 seconds, while the coffee-maker takes 10 minutes (or 600 seconds) to brew coffee. Overall, the microwave is more energy-efficient for reheating coffee in small amounts.