Task: Question Answering
Input (English): Problem: excluding the stoppages, the speed of a bus is 12 km / hr and including the stoppages the speed of the bus is 6 km / hr. for how many minutes does the bus stop per hour ?
Options: a. 15 min, b. 30 min, c. 12 min, d. 20 min, e. 18 min
Output (English): b