Task: Question Answering
Input (English): Problem: a cyclist rides a bicycle 7 km at an average speed of 10 km / hr and again travels 10 km at an average speed of 7 km / hr . what is the average speed for the entire trip ? 
Options: a ) 7.59 , b ) 7.79 , c ) 7.99 , d ) 8.19 , e ) 8.39
Output (English): c