What was the average speed of Jojo and Henry?

Jojo and Henry started from the same point and traveled on a straight course in opposite directions, exactly two hours at which time they were 208 miles apart. Jojo traveled on average 8 mph faster than Henry. What was the average speed of each, for the 2-hour trip?|||Speed of Jojo鈥攕:


2(s + s - 8) = 208


2s - 8 = 104


2s = 112


s = 56





Speed of Henry:


= 56 - 8


= 48








Answer: Jojo, 56 mph; Henry, 48 mph|||Being 208 miles apart after 2 hours, their separation velocity is, together, 104 miles per hour.





If you designate their respective velocities as j and h, you can write





1). j + h = 104 mph ( from which their average speed is 52 mph.) and





2). j = h + 8 mph or





3). j - h = 8 mph.





Adding 1) and 3) gives 2j = 112 mph from which


j = 56 mph. Plugging this result into 1) or 2) gives h = 48 mph.|||Let J = avg speed of Jojo


Let H = avg speed of Henry





2J + 2H = 208


J + H = 104


J = H + 8





(H + 8) + H = 104


2H + 8 = 104


2H = 96


H = 48





J = 48 + 8


J = 56





Jojo's average speed was 56mph and Henry's was 48mph