A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. Find the length of train ?  Choose the correct answer:  A) 45 m  B) 50 m  C) 55 m  D) 60 m  E) 65 m
Explanation:   First person speed = 2*(5/18) = 5/9 m/sec   Second person speed = 4*(5/18) = 10/9 m/sec   Let the length of train is x metre and speed is y m/sec   then,   x /y−5/9=9   =&gt;9y−5=x   =&gt;9y−x=5.....(i)Also,   x /y−10/9=10   90y−9x=100.....(ii)from (i) and (ii), we get,x=50   So length of train is 50 metre   Option 50 m
<result>B</result>
A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. Find the length of train ?