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'.

[Q]: Problem: two trains 120 m and 160 m long run at the speed of 60 km / hr and 40 km / hr respectively in opposite directions on parallel tracks . the time which they take to cross each other is ? 
Options: a ) 10.9 , b ) 10.7 , c ) 10.3 , d ) 10.08 , e ) 10.2
[A]: d


[Q]: Problem: two trains are approaching each other at 60 mph each . the length of each train is 1 / 6 miles . when the two locomotives ( engines ) meet , how many seconds will it take for them to pass each other completely ? 
Options: a ) 8 sec , b ) 11 sec , c ) 12 sec , d ) 10 sec , e ) 15 sec
[A]: d


[Q]: Problem: if a boat is rowed downstream for 500 km in 5 hours and upstream for 240 km in 6 hours , what is the speed of the boat and the river ? 
Options: a ) 70 , 30 , b ) 30 , 70 , c ) 70 , 70 , d ) 30 , 30 , e ) 80 , 50
[A]:
a