Answers

2015-06-01T20:16:45+05:30
Avg speed = (speed1+speed2)/2

speed1= 250/5
          =  50 m/s
speed2= 250/5
          = 50m/s

avg speed=( 50+50)/2
               = 50 m/s

avg velocity =0 because the displacement is 0 as the bus came back to Delhi covering the same distance  
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2015-06-02T09:35:34+05:30
Distance =250 +250=500km
time=5hr+5hr=10hr
average speed=total distance\ total time
average speed=500\10=50k\h
velocity=0
because displacement is 0 as body comes back 

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