A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 5 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?	Options
A) 480  B) 287  C) 289  D) 270  E) 600
1/x - 1/20 = -1/24   x = 120   120 * 5= 
<gadget id="calculator">120 * 5</gadget>
<output>600</output>
600   Answer: 600
<result>E</result>
A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 5 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?