John traveled the entire 60 miles tirp. if he did the first 12 miles of a constant rate 24 miles per hour and the remaining trip of a constant rate 48 miles per hour, what is the his average speed, in miles per hour? A. 20 mph B. 24 mph C. 30 mph D. 32 mph E. 40 mph The OA is E . Is there a strateg...