1) A leak in the bottom of a tank can empty the full tank in 8 hours. An inlet pipe fills water at the rate of 6 liters a minute. When the tank is full, the inlet is opened and due to the leak, the tank is empty in 12 hours. How many liters does the cistern hold ? A) 7980 B) 7860 C) 8640 D) 8340 Answer: Option CExplanation:Work done by the inlet in 1 hour =(18−112) =124. Work done by the inlet in 1 min. =(124×160) =11440. ∴ Volume of 11440 part =6 liters. ∴ Volume of whole =(1440×6) liters = 8640 liters.