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: the racing magic takes 50 seconds to circle the racing track once . the charging bull makes 40 rounds of the track in an hour . if they left the starting point together , how many minutes will it take for them to meet at the starting point for the second time ? 
Options: a ) 3 , b ) 6 , c ) 9 , d ) 12 , e ) 15

A: e
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Q: Problem: b completes a work in 9 days . a alone can do it in 10 days . if both work together , the work can be completed in how many days ? 
Options: a ) 3.75 days , b ) 4.73 days , c ) 5.75 days , d ) 6.75 days , e ) 7.73 days

A:
b
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