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: two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 21 seconds . the ratio of their speeds is ? 
Options: a ) 3 / 6 , b ) 3 / 2 , c ) 2 / 3 , d ) 3 / 5 , e ) 5 / 2

Answer: c


Question: Problem: some persons can do a piece of work in 8 days . two times the number of these people will do half of that work in ? 
Options: a ) 2 , b ) 4 , c ) 5 , d ) 6 , e ) 8

Answer: a


Question: Problem: how many revolutions will a circular wheel make to travel a distance of 3 km , given that the radius is 2.4 m ? 
Options: a ) 11085.7 , b ) 15085.7 , c ) 35085.7 , d ) 15015.7 , e ) 15083.7

Answer:
a