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: calculate the speed of a boat in still water ( in km / hr ) if in one hour , the boat goes 10 km / hr downstream and 4 km / hr upstream .
Options: a ) 7 kmph , b ) 8 kmph , c ) 9 kmph , d ) 7 kmph , e ) 6 kmph

Answer: a

Question: Problem: a man is standing on a railway bridge which is 180 m long . he finds that a train crosses the bridge in 20 seconds but himself in 8 seconds . find the length of the train and its speed
Options: a ) 50 km , b ) 52 km , c ) 54 km , d ) 56 km , e ) 58 km

Answer: c

Question: Problem: there are 20 poles with a constant distance between each pole . a car takes 24 second to reach the 12 th pole . how much will it take to reach the last pole .
Options: a ) 41.4543 , b ) 41.4545 , c ) 41.45128 , d ) 41.41288 , e ) 41.41222

Answer:
b