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: a can finish a piece of work in 12 days . b can do it in 20 days . they work together for 9 days and then a goes away . in how many days will b finish the work ? 
Options: a ) 6 days , b ) 4 days , c ) 5 days , d ) 3 days , e ) 7 days
[EX A]: c

[EX Q]: Problem: in what time will a train 100 meters long cross an electric pole , if its speed is 162 km / hr 
Options: a ) 8.5 seconds , b ) 2.22 seconds , c ) 3.5 seconds , d ) 2.5 seconds , e ) 2.6 seconds
[EX A]: b

[EX Q]: Problem: a car is 15 minutes late by running at a speed of 4 / 5 th of its actual speed . the actual time taken by the car to cover that distance is : 
Options: a ) 30 minutes , b ) 1 hour , c ) 2 hours , d ) 3 hours , e ) none of these
[EX A]:
b