Question 1194491
There are two trains.
 The rabbit heads north on the expressway at 45kph. 
 Exactly 12 minutes after, Panther follows at a steady speed of 54kph.
 How long does it take Panther to overtake the Rabbit? 
:
Notice that when one train catches the other, they will travel the same distance
:
Change 12 min to hrs.  12/60 = .2 hrs. We need to do this because the speed is
in km per hour
let t = travel time (in hrs) of P
then R leaves 12 min earlier, therefore
(t+.4) = travel time of R
:
P's dist = R's dist
54t = 45(t+.4) 
54t = 45t + 18
54 - 45t = 18
9t = 18
t = 18/9
t = 2 hrs for P to catch R
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Check, find the actual dist for each, should be equal
2 * 54 = 108 km
2.4 * 45 = 108