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'.

[EX Q]: Problem: a train is 300 meter long is running at a speed of 35 km / hour . in what time will it pass a bridge of 115 meter length ? 
Options: a ) 29 , b ) 23 , c ) 47.119 , d ) 44.586 , e ) 42.686
[EX A]: e

[EX Q]: Problem: a train is 485 meter long is running at a speed of 45 km / hour . in what time will it pass a bridge of 140 meter length 
Options: a ) 20 seconds , b ) 30 seconds , c ) 40 seconds , d ) 50 seconds , e ) none of these
[EX A]: d

[EX Q]: Problem: calculate how much time could be saved if the train would run at its usual speed , given that it ran at 2 / 3 of its own speed and got to its destination in 20 hours ? 
Options: a ) 5.67 hrs , b ) 9.67 hrs , c ) 8.95 hrs , d ) 8.67 hrs , e ) 6.67 hrs
[EX A]:
d