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a car is moving on straight road covers 1/3 of distance with a speed of 20km/h and rest with speed of 60km/h the average speed of car is???

Answers (1)

Let the distnace travelled by a car on staright path  be x.

The one thrid distance is covered with speed of 20 km/h and the rest two- third distance with speed of 60 km/h

Thus, 

time required for the one third of the journey is 

fraction numerator begin display style bevelled x over 3 end style over denominator 20 end fraction equals x over 60 

The time required for the rest part of the journey is 

fraction numerator begin display style bevelled fraction numerator 2 x over denominator 3 end fraction end style over denominator 60 end fraction equals x over 90 

Thus the total time taken to complete the journey is,

x over 60 plus x over 90 equals x over 36  

Thus, the average speed is,

 

Average speed = Total distance travelled/ total time taken 

A v e r a g e space s p e e d space equals space fraction numerator x over denominator begin display style bevelled x over 36 end style end fraction
T h u s space a v e r a g e space s p e e d space space equals 36 space k m divided by h space

Posted by

Satyajeet Kumar

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