In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: a train overtakes two person 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 . the length of the train is : 
Options: a ) 45 m , b ) 50 m , c ) 54 m , d ) 72 m , e ) none of these
[A]: b


[Q]: Problem: a 600 meter long train crosses a signal post in 15 seconds . how long will it take to cross a 3 kilometer long bridge , at the same speed ? 
Options: a ) 4 min , b ) 2 min , c ) 8 min , d ) 9 min , e ) 1.5 min
[A]: e


[Q]: Problem: two persons a and b can complete a piece of work in 18 days and 24 days respectively . if they work together , what part of the work will be completed in 2 days ? 
Options: a ) 7 / 36 , b ) 9 / 35 , c ) 4 / 37 , d ) 8 / 35 , e ) 5 / 3
[A]:
a