Two pipes can fill a tank in 10 hrs. and 12 hrs. respectively while a third pipe empties the full tank in 20 hrs. If all the three pipes operate together , in how much time the tank will be filled ?
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Answer:
Two pipes can fill a tank in 10 hrs. and 12 hrs. respectively while a third pipe empties the full tank in 20 hrs. If all the three pipes operate together , in how much time the tank will be filled ? 7.5 hrs.