Pramod travels for 14 hours 40 min. He covers one half of the journey by train at 60 kmph and the rest half by road at 50 kmph. What is the total distance traveled by Pramod (in km)

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Pramod travels for 14 hours 40 min. He covers one half of the journey by train at 60 kmph and the rest half by road at 50 kmph. What is the total distance traveled by Pramod (in km)

+1 vote

Let's total time=t=14hrs 40 min=880 min............(i)

total distance travelled=x

half distance=d1=d2=x/2........................................(ii)

Speed=s1=60km/hr=1km/min..............................(iii)

s2=50km/hr=50/60 km/min.................................(iv)

t=d/s=[(d1/s1)]+[(d2/s2)]

880=[(x/2)/1]+[(x/2)/(50/60)]................from (i) to (iv)

x=800

ans is 800 km

0 votes

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So in other words while measuring average speed we have to check for how long what speed was maintained into the calculation.

The average speed in this case turns out to be 54.54 just a little less than what you came up with hence the slight error.