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: in what time will a railway train 80 m long moving at the rate of 40 kmph pass a telegraph post on its way ? 
Options: a ) 3 , b ) 5 , c ) 4 , d ) 6.4 , e ) 7.2

A: e
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Q: Problem: convert 0.34 in to a vulgar fraction ? 
Options: a ) 18 / 50 , b ) 16 / 50 , c ) 17 / 50 , d ) 19 / 50 , e ) none

A: c
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Q: Problem: 20 beavers , working together in a constant pace , can build a dam in 3 hours . how many b hours will it take 12 beavers that work at the same pace , to build the same dam ? 
Options: a ) 2 . , b ) 4 . , c ) b = 5 . , d ) b = 6 . , e ) b = 8 .

A:
c
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