Question of The Day26-08-2021

Train A started from Kanpur station and at the same time train B started from Agra station toward each other. After crossing each other they take 4 hours and 36 hours respectively to reach the destination (i.e. Start point of other train). If the speed of train A is 180 km/h, then find the speed of train B.


Correct Answer : b ) 60 km/h

Explanation :

According to the question

We know that,

\({s1 \over s2}=\sqrt{T_2 \over T_1}\)

Where, s1 = speed of train A and s2 = Speed of train B and T1 be the time taken by train A after crossing and T2 be the time taken by the train B after crossing.

T1 = 4hrs and T2 = 36hrs

\(s1 \over s2\)=\(\sqrt{36 \over 4}\)\(\sqrt 9\)

\(s_1\over s_2\)=\(3 \over 1\)

Speed of train A = 180km/h

3unit = 180 km/h

1 unit = 60 km/h

Speed of train B = 60km/h

Hence, (b) is the correct answer.



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