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: walking with 5 / 4 of my usual speed , i miss the bus by 5 minutes . what is my usual time ? 
Options: a ) 18 , b ) 19 , c ) 20 , d ) 22 , e ) 24

A: c
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Q: Problem: a boat covers a certain distance downstream in 1 hour , while it comes back in 1 ½ hours . if the speed of the stream be 3 kmph , what is the speed of the boat in still water ? 
Options: a ) 12 kmph , b ) 13 kmph , c ) 14 kmph , d ) 15 kmph , e ) none

A: d
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Q: Problem: a train 250 m long running at 72 kmph crosses a platform in 20 sec . what is the length of the platform ? 
Options: a ) 150 m , b ) 200 m , c ) 250 m , d ) 270 m , e ) 300 m

A:
a
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