The answer would be E= 27 miles
You would start out by figuring out how many hours it would take him to swim by dividing 6/2 to get 3 then you would find out how long it would take him to run by dividing 15/6 to get 2.5 and you would add that to the 3 to get 5.5 and subtract that by 7 to get 1.5 which is how long he will have to complete leg 3 so you would take 18x1.5 to get 27 mph
