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: the length of the bridge , which a train 140 metres long and travelling at 45 km / hr can cross in 30 seconds , is : 
Options: a ) 200 m , b ) 235 m , c ) 245 m , d ) 250 m , e ) 270 m
[EX A]: b

[EX Q]: Problem: three pipes of same capacity can fill a tank in 8 hours . if there are only two pipes of same capacity , the tank can be filled in . 
Options: a ) 11 hours , b ) 12 hours , c ) 15 hours , d ) 16 hours , e ) 17 hours
[EX A]: b

[EX Q]: Problem: what is the speed of the stream if a canoe rows upstream at 3 km / hr and downstream at 12 km / hr 
Options: a ) 1 kmph , b ) 4 kmph , c ) 3 kmph , d ) 2 kmph , e ) 4.5 kmph
[EX A]:
e