Question
Tap P can fill the tank in 5 hours and Tap Q can empty it in 7(1/2) hours. Tap P starts filling and they opened for 1 hour each alternatively. In what time will the tank be full?
Solution
2 Hours = 1 work doneย ย ย ย ย
Last work will be done by P Therefore, 15 -3 = 12 
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