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: 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 ) 255 , b ) 267 , c ) 235 , d ) 277 , e ) 211

A: c
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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

A: d
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Q: Problem: a can do a piece of work in 10 days and b alone can do it in 20 days . how much time will both take to finish the work ? 
Options: a ) a ) 5.333 , b ) b ) 6 , c ) c ) 6.666 , d ) d ) 8.333 , e ) e ) 9

A:
c
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