Task: Question Answering
Input (English): Problem: a person walking at 10 kmph reaches his office 10 minutes late . if he walks at 15 kmph , he reaches there 10 minutes earlier . how far is the office from his house ? 
Options: a ) 5 km , b ) 15 km , c ) 8 km , d ) 10 km , e ) 20 km
Output (English): d