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: two trains of length 100 meters and 200 meters are 840 meters apart . they are moving towards each other on parallel tracks , at speeds of 54 km / h and 72 km / h . after how many seconds will the trains meet ? 
Options: a ) 20 , b ) 22 , c ) 24 , d ) 26 , e ) 28
[EX A]: c

[EX Q]: Problem: a man can row upstream at 20 kmph and downstream at 60 kmph , and then find the speed of the man in still water ? 
Options: a ) 32 kmph , b ) 34 kmph , c ) 30 kmph , d ) 45 kmph , e ) 40 kmph
[EX A]: e

[EX Q]: Problem: find the area of a cuboid of length 8 cm , breadth 10 cm . and height 12 cm . 
Options: a ) 900 cm cube , b ) 910 cm cube , c ) 920 cm cube , d ) 930 cm cube , e ) 960 cm cube
[EX A]:
e