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'.
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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: when working alone , painter w can paint a room in 2 hours , and working alone , painter x can paint the same room in r hours . when the two painters work together and independently , they can paint the room in 3 / 4 of an hour . what is the value of r ? 
Options: a ) 3 / 4 , b ) 1 [ 1 / 5 ] , c ) 1 [ 2 / 5 ] , d ) 1 [ 3 / 4 ] , e ) 2

Answer: b


Question: Problem: if two painters can complete two rooms in two hours , how many rooms painted if 10 painters work for 6 hours ? 
Options: a ) 35 , b ) 25 , c ) 20 , d ) 30 , e ) 15

Answer:
d