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: noelle walks from point a to point b at an average speed of 6 kilometers per hour . at what speed , in kilometers per hour , must noelle walk from point b to point a so that her average speed for the entire trip is 7 kilometers per hour ? 
Options: a ) 6.75 , b ) 7 , c ) 7.25 , d ) 7.5 , e ) 8.4
[EX A]: 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 train running at the speed of 60 km / hr crosses a pole in 15 seconds . find the length of the train . 
Options: a ) 150 m , b ) 145 m , c ) 240 m , d ) 135 m , e ) 250 m
[EX A]:
e