Question 1058742
<pre><b>
Since d = rt, after 2 minutes (120 seconds), the robber would be 
(42)(120) or 5040 meters ahead of the cop.  The cop's approach 
rate to the robber is then 42-40 or 2 m/s.  So since t = d/r, it 
would take the cops an additional 5040/2 = 2520 seconds to catch 
up.  So adding that to the 120 seconds, we get that 2640 seconds 
passed from when the robber left until the cop caught him.  And 
2640 seconds = 44 minutes.   

Edwin</pre></b>