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: 20 beavers , working together in a constant pace , can build a dam in 18 hours . how many hours will it take 12 beavers that work at the same pace , to build the same dam ?
Options: a ) 22 . , b ) 24 . , c ) 30 . , d ) 36 , e ) 38 .
[EX A]: c

[EX Q]: Problem: a train passes a station platform in 35 sec and a man standing on the platform in 20 sec . if the speed of the train is 54 km / hr . what is the length of the platform ?
Options: a ) 228 , b ) 240 , c ) 225 , d ) 166 , e ) 1811
[EX A]: c

[EX Q]: Problem: a train leaves mumabai at 9 am at a speed of 40 kmph . after one hour , another train leaves mumbai in the same direction as that of the first train at a speed of 50 kmph . when and at what distance from mumbai do the two trains meet ?
Options: a ) 276 , b ) 271 , c ) 200 , d ) 278 , e ) 268
[EX A]:
c