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 man can row downstream at 16 kmph and upstream at 10 kmph . find the speed of the man in still water and the speed of stream respectively ? 
Options: a ) 3 , b ) 5 , c ) 6 , d ) 4 , e ) 9

A: a
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Q: Problem: when the perimeter of a regular polygon is divided by 5 , the length of a side is 25 . what is the name of the polygon ? what is the perimeter ? 
Options: ['a ) 125', 'b ) 126', 'c ) 127', 'd ) 128', 'e ) 129']

A: a
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Q: Problem: nicky and cristina are running a 400 meter race . since cristina is faster than nicky , she gives him a 12 second head start . if cristina runs at a pace of 5 meters per second and nicky runs at a pace of only 3 meters per second , how many seconds will nicky have run before cristina catches up to him ? 
Options: a ) 40 , b ) 25 , c ) 35 , d ) 30 , e ) 50

A:
d
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