A bus leaves the station traveling at 25 mph. Nine hours later a car leaves the station traveling at 70 mph, and heads in the same direction. How far from the station will the two meet?

Question

whpalmer4 · Answer

Write the equations for distance traveled as a function of time.  For example, the bus travels 25 miles per hour, so its position will be 25t.  Also, figure out how far the bus will travel before the car starts.  The distance the bus traveled in that 9 hours + the equation for the bus = the equation for the car at the time they meet.  Solve for the time.

Alternative approach: find out how much of a head start the bus gets (25 mph * 9 hours = ?)  Divide that by the difference in speed between the two to find out how long it will take to make up that head start.