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 train 280 m long , running with a speed of 72 km / hr will pass a tree in 
Options: a ) 14 sec , b ) 15 sec , c ) 16 sec , d ) 20 sec , e ) none
a

Problem: in what time will a train 100 metres long cross an electric pole , if its speed be 144 km / hr ? 
Options: a ) 2.5 sec , b ) 4.25 sec , c ) 5 sec , d ) 12.5 sec , e ) none
a

Problem: a train covers a distance of 18 km in 10 min . if it takes 9 sec to pass a telegraph post , then the length of the train is ? 
Options: a ) 120 m , b ) 180 m , c ) 270 m , d ) 220 m , e ) 280 m

c