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'.

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

Problem: two trains of equal length , running with the speeds of 60 and 40 kmph , take 36 seconds to cross each other while they are running in the same direction . what time will they take to cross each other if they are running in opposite directions ? 
Options: a ) 10 sec , b ) 16 sec , c ) 19 sec , d ) 7.2 sec , e ) 13 sec
d

Problem: two trains of length 400 m and 200 m are 200 m apart . they start moving towards each other on parallel tracks , at speeds 54 kmph and 36 kmph . after how much time will the trains meet ? 
Options: a ) 8 sec , b ) 20 / 7 sec , c ) 33 / 7 sec , d ) 21 / 7 sec , e ) 32 / 7 sec

a