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'.
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Question: Problem: it will take 16 days for mary to complete a certain task alone . she worked for 8 days before she was joined by her sister . both of them completed the remaining task in 2 and half days . if her sister had joined her when she started the task , how many days would it have taken ? 
Options: a ) 6 , b ) 8 , c ) 2 , d ) 5 , e ) 4

Answer: d


Question: Problem: a train is 360 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 ) 27 seconds , c ) 30 seconds , d ) 40 seconds , e ) 50 seconds

Answer: d


Question: Problem: the length of the bridge , which a train 160 metres long and travelling at 45 km / hr can cross in 30 seconds , is : 
Options: a ) 200 m , b ) 215 m , c ) 245 m , d ) 250 m , e ) 270 m

Answer:
b