Task: Question Answering
Input (English): Problem: 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. 487, c. 481, d. 729, e. 600
Output (English): e