Task: Question Answering
Input (English): Problem: a man can row a distance of 5 km in 60 min with the help of the tide . the direction of the tide reverses with the same speed . now he travels a further 30 km in 10 hours . how much time he would have saved if the direction of tide has not changed ? 
Options: a ) 2 , b ) 8 , c ) 4 , d ) 6 , e ) 5
Output (English): c