Task: Question Answering
Input (English): Problem: a man complete a journey in 20 hours . he travels first half of the journey at the rate of 10 km / hr and second half at the rate of 15 km / hr . find the total journey in km . 
Options: a ) 220 km , b ) 240 km , c ) 230 km , d ) 232 km , e ) 234 km
Output (English): b