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 250 m long running at 72 kmph crosses a platform in 15 sec . what is the length of the platform ? 
Options: a ) 50 m , b ) 200 m , c ) 250 m , d ) 270 m , e ) 300 m
a

Problem: a copy machine , working at a constant rate , makes 40 copies per minute . a second copy machine , working at a constant rate , makes 55 copies per minute . working together at their respective rates , how many copies do the two machines make in half an hour ? 
Options: a ) 90 , b ) 2,700 , c ) 4,500 , d ) 5,400 , e ) 2,850
e

Problem: amit and ananthu can do a work in 15 days and 30 days respectively . amit started the work and left after 3 days . ananthu took over and completed the work . in how many days was the total work completed ? 
Options: a ) 28 days , b ) 20 days , c ) 23 days , d ) 25 days , e ) 27 days

e