Task: Question Answering
Input (English): Problem: a car travels first 160 km at 75 km / hr and the next 160 km at 70 km / hr . what is the average speed for the first 320 km of the tour ? 
Options: a ) 71.11 , b ) 71.12 , c ) 72.4 , d ) 71.17 , e ) 71.13
Output (English): c