An outlet pipe empties a tank which is full in 5 hours. If the inlet pipe is kept open, which lets water in at the rate of 4 litres/min then outlet pipe would take 3 hours longer. Find the capacity of the tank.	Choose the correct choice from the following answers.
A) 8600 litres
B) 3200 litres
C) 12800 litres
D) 11200 litres
E) 13200 litres
Let the rate of outlet pipe be x liters/hour;   Rate of inlet pipe is 8 litres/min, or  4*60= 
<gadget id="calculator"> 4*60</gadget>
<output>240</output>
240 liters/hour;   Net outflow rate when both pipes operate would be x-240 liters/hour.   Capacity of the tank= x*5 hours = (x-240)*(5+3) hours   5x=(x-240)*8 --&gt; x=640 --&gt; capacity = 5x = 3200 liters.   Answer: 3200 litres.
<result>B</result>
An outlet pipe empties a tank which is full in 5 hours. If the inlet pipe is kept open, which lets water in at the rate of 4 litres/min then outlet pipe would take 3 hours longer. Find the capacity of the tank.