instruction:
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'.
question:
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
answer:
d


question:
Problem: a river boat leaves silver town and travels upstream to gold town at an average speed of 3 kilometers per hour . it returns by the same route at an average speed of 7 kilometers per hour . what is the average speed for the round - trip in kilometers per hour ? 
Options: a ) 4.2 , b ) 7.1 , c ) 7.2 , d ) 7.5 , e ) 8.0
answer:
a


question:
Problem: a train running at the speed of 30 km / hr crosses a pole in 9 sec . what is the length of the train ? 
Options: a ) 75 m , b ) 180 m , c ) 324 m , d ) can not be determined , e ) none of these
answer:

a