<PRE><B>Question 1118157</B>
a train travels a certain journey and is supposed to arrive at midday.
 when its average speed is 40km/h, it arrives at 1pm
 when its average speed is 48km/hr it arrives at 11am.
 what is the length of the journey?
:
let d = the length of the journey
The arrival times differ by 2 hrs
:
Write a time equation
40km/h time - 48km/h time = 2 hrs
{{{d/40}}} - {{{d/48}}} = 2 
multiply equation by 240
240*{{{d/40}}} - 240*{{{d/48}}} = 2(240)
Cancel the denominators
6d - 5d = 480
d = 480 km is the distance
:
:
Check this, Find the actual time of each
480/40 = 12 hrs
480/48 = 10 hrs
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differs = 2 hrs </PRE>