Task: Question Answering
Input (English): Problem: without stoppages , a train travels certain distance with an average speed of 300 km / h , and with stoppages , it covers the same distance with an average speed of 200 km / h . how many minutes per hour the train stops ? 
Options: a ) 20 , b ) 21 , c ) 22 , d ) 23 , e ) 24
Output (English): a