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 equal length are running on parallel lines in the same direction at 46 km / hr and 36 km / hr . the faster train catches and completely passes the slower train in 54 seconds . what is the length of each train ( in meters ) ? 
Options: a ) 45 , b ) 55 , c ) 65 , d ) 75 , e ) 85
[EX A]: d

[EX Q]: Problem: a hall 36 m long and 15 m broad is to be paved with stones , each measuring 8 dm by 5 dm . the number of stones required is : 
Options: a ) 180 , b ) 1800 , c ) 18 , d ) 18000 , e ) 1350
[EX A]: e

[EX Q]: Problem: 12 machines can do a work in 10 days . how many machines are needed to complete the work in 40 days ? 
Options: a ) 10 , b ) 3 , c ) 4 , d ) 7 , e ) 5
[EX A]:
b