john is participating in a triathlon. he swims a rate of 2 mph and runs at a rate of 6 mph. the course is broken down in the following manner: leg 1- swim 6 miles, leg 2- run 15 miles, leg 3- bike 18 miles. how fast will john have to bike to finish the triathlon in exactly 7 hours?
answers:
a. 6 mph b. 9 mph c. 12 mph d. 18 mph e. 27 mph
*also explain how you got your answer also