A windmill is taking advantage of strong air currents in order to produce electrical energy. On a typical day the wind speed is around 20 mph and in that speed the windmill produces 700 kw/h (kilowatts per hour). On a stormy day a windmill produces 20% more energy. How much kw/h can three windmills produce in two hours on a stormy day?	Options:
A) 2880.  B) 4860.  C) 5780.  D) 5040.  E) 6380.
Efficiency per machine = 700 watt/hr   Efficiency due to increase in wind speed = 700*120% =&gt; 840 watt/hr   Production by each machine in 2 hours is  840*2= 
<gadget id="calculator"> 840*2</gadget>
<output>1_680</output>
&gt; 1680 watt   Production by 3 machines=&gt; 1680 watt * 3 = 5040 watt   Answer will be (5040.)
<result>D</result>
A windmill is taking advantage of strong air currents in order to produce electrical energy. On a typical day the wind speed is around 20 mph and in that speed the windmill produces 700 kw/h (kilowatts per hour). On a stormy day a windmill produces 20% more energy. How much kw/h can three windmills produce in two hours on a stormy day?