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'.

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
c

Problem: a can do a piece of work in 8 days and b alone can do it in 12 days . how much time will both take to finish the work ?
Options: a ) a ) 4.8 , b ) b ) 6.333 , c ) c ) 7.333 , d ) d ) 8.5 , e ) e ) 9
a

Problem: in an examination , a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer . if he attempts all 80 questions and secures 120 marks , the number of questions he attempts correctly , is :
Options: a ) 35 , b ) 46 , c ) 42 , d ) 30 , e ) 40
e