Question 1149270
Bob leaves Pittsburgh traveling west.
 Jim leaves from the same point two hours later and travels the same route at 18 miles per hour faster than bob.
 If Jim wants to catch up four hours after he leaves, how fast will he have to go?
;
let s = Jim's speed
then
(s-18) = Bob's  speed
:
When J catch's B it will be 6 hrs after B departed (2 + 4)
They will have traveled the same distance
Write a distance equation, dist = time * speed
6(s-18) = 4s
6s - 108 = 4s
6s - 4s = 108
2s = 108
s = 108/2
s = 54 mph
:
Check find the actual dist each traveled B's speed 54 - 18 = 36 mph
6 * 36 = 216 mi
4 * 54 = 216