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'.

[EX Q]: Problem: a man can row 4 kmph in still water . when the river is running at 1.8 kmph , it takes him 1 hour to row to a place and black . what is the total distance traveled by the man ? 
Options: a ) 7.13 , b ) 6.19 , c ) 4.12 , d ) 3.19 , e ) 4.21
[EX A]: b

[EX Q]: Problem: if a train , travelling at a speed of 360 kmph , crosses a pole in 5 sec , then the length of train is ? 
Options: a ) 381 m , b ) 112 m , c ) 500 m , d ) 125 m , e ) 433 m
[EX A]: c

[EX Q]: Problem: worker a takes 8 hours to do a job . worker b takes 10 hours to do the same job . how long should it take both a and b , working together but independently , to do the same job ? 
Options: a ) 70 hours , b ) 40 / 9 hours , c ) 9 hours , d ) 16 hours , e ) 20 hours
[EX A]:
b