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: two cars start at the same time from opposite ends of a highway that is 333 miles long . one car is riding at 54 mph and the second car is riding at 57 mph . how long after they begin will they meet ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 4 , e ) 5
[EX A]: c

[EX Q]: Problem: a boat having a length 4 m and breadth 2 m is floating on a lake . the boat sinks by 1 cm when a man gets on it . the mass of the man is : 
Options: a ) 12 kg , b ) 60 kg , c ) 72 kg , d ) 80 kg , e ) none of these
[EX A]:
d