Question 624733
Car 1 leaves point A at 5:30 pm, driving due south at an average speed of 35 mph. Car 2 leaves point A at 6:30 pm, driving due north at an average speed of 45 mph. How far apart will the drivers be at 9:30 pm?
<pre>
When car 2 leaves at 6:30, 1 hour after Car 1, Car 1 is 35 miles from Car 2.
They then are separating at the rate of 35mph+45mph or 80mph, so after 
3 hours, at 9:30 they will have separated an additional 3×80 = 240 miles. So
they will be 35+240 or 275 miles apart at 9:30.

Edwin</pre>