A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 1 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold? Choose the correct choice from the following options.
A) 480  B) 120  C) 289  D) 270  E) 927
1/x - 1/20 = -1/24   x = 120   120 * 1= 
<gadget id="calculator">120 * 1</gadget>
<output>120</output>
120   Answer: 120
<result>B</result>
A cistern has a leak which would empty the cistern in 20 minutes. A tap is turned on which admits 1 liters a minute into the cistern, and it is emptied in 24 minutes. How many liters does the cistern hold?