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 man and a boy complete a work together in 24 days . if for the last 6 days man alone does the work then it is completed in 26 days . how long the boy will take to complete the work alone ?
Options: a ) 72 days , b ) 20 days , c ) 24 days , d ) 36 days , e ) 34 days
[EX A]: a

[EX Q]: Problem: working alone , pump a can empty a pool in 6 hours . working alone , pump b can empty the same pool in 9 hours . working together , how many minutes will it take pump a and pump b to empty the pool ?
Options: a ) 192 , b ) 200 , c ) 208 , d ) 216 , e ) 224
[EX A]: d

[EX Q]: Problem: a train covers a distance of 100 km in 1 hour . if its speed is decreased by 20 km / hr , the time taken by the car to cover the same distance will be ?
Options: a ) 1 hr , b ) 1 hr 15 min , c ) 50 min , d ) 1 hr 30 min , e ) 1 hr 45 min
[EX A]:
b