Task: Question Answering
Input (English): Problem: a student travels from his house to school at 10 km / hr and reaches school 2 hours late . the next day he travels 15 km / hr and reaches school 1 hour early . what is the distance between his house and the school ? 
Options: a ) 60 , b ) 70 , c ) 80 , d ) 90 , e ) 100
Output (English): d