Task: Question Answering
Input (English): Problem: a cistern can be filled by a tap in 2 hours while it can be emptied by another tap in 4 hours. if both the taps are opened simultaneously then after how much time will the cistern get filled ?
Options: a. 2 hr, b. 5 hr, c. 7 hr, d. 1 hr, e. 4 hr
Output (English): e