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 motorcyclist started riding at highway marker a , drove 120 miles to highway marker b , and then , without pausing , continued to highway marker c , where she stopped . the average speed of the motorcyclist , over the course of the entire trip , was 40 miles per hour . if the ride from marker a to marker b lasted 3 times as many hours as the rest of the ride , and the distance from marker b to marker c was half of the distance from marker a to marker b , what was the average speed , in miles per hour , of the motorcyclist while driving from marker b to marker c ? 
Options: a ) 40 , b ) 45 , c ) 50 , d ) 55 , e ) 67.5
e

Problem: a train 120 m long running at 60 kmph crosses a platform in 20 sec . what is the length of the platform ? 
Options: a ) 213 , b ) 298 , c ) 350 , d ) 726 , e ) 267
a

Problem: a 1200 m long train crosses a tree in 120 sec , how much time will i take to pass a platform 500 m long ? 
Options: a ) 266 sec , b ) 170 sec , c ) 776 sec , d ) 166 sec , e ) 997 sec

b