One pump drains one-half of a pond in 1 hours, and then a second pump starts draining the pond. The two pumps working together finish emptying the pond in one-half hour. How long would it take the second pump to drain the pond if it had to do the job alone? Select the correct option
A) 1 hour	B) 1.2 hour	C) 3 hours	D) 5 hours	E) 6 hours
The tricky part here, I believed is one half hour = 1/2. Then everything would be easy.   We have the 1st pump working rate/hour = 1/2 : 1 = 1/2   Working rate of 2 pumps: 1/2 : 1/2 = 1.   Working rate of 2nd pump: 1 -1/2 = 1/2 --&gt; Time taken for the 2nd pump to finish: 1 : 1/2 = 2/1= 
<gadget id="calculator">2/1</gadget>
<output>2</output>
2 hours.   3 hours
<result>C</result>
One pump drains one-half of a pond in 1 hours, and then a second pump starts draining the pond. The two pumps working together finish emptying the pond in one-half hour. How long would it take the second pump to drain the pond if it had to do the job alone?