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: a train 150 m long crosses a platform 130 m long in 20 sec ; find the speed of the train ? 
Options: a ) 50 , b ) 60 , c ) 55 , d ) 45 , e ) 53

A: a
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Q: Problem: a can do a piece of work 60 days . b can do work in 20 days . in how many days they will complete the work together ? 
Options: a ) 12 days , b ) 16 days , c ) 15 days , d ) 17 days , e ) 18 days

A: c
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Q: Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively , while the third empty it in 40 hr . if all pipes are opened simultaneously , then the cistern will be filled in 
Options: a ) 6.32 hr , b ) 8 hr , c ) 8.5 hr , d ) 10 hr , e ) none of these

A:
a
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