Task: Question Answering
Input (English): Problem: tom traveled the entire 80 miles trip . if he did the first 30 miles of at a constant rate 30 miles per hour and the remaining trip of at a constant rate 50 miles per hour , what is the his average speed , in miles per hour ? 
Options: a ) 55 mph , b ) 50 mph , c ) 40 mph , d ) 60 mph , e ) 70 mph
Output (English): c