Algebra  K11Mr. Rapid always starts driving on a road at exactly 7:00 a.m.
If he drives on cruise control at 24 miles per hour, he arrives at work late.
If he sets the cruise control to 48 miles per hour, he arrives at work early.
The amount of time he is early is also the amount of time he is late.

How fast should he go to get to his office exactly on time?