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: if 8 people take an hour to complete a piece of work , then how long should 16 people will take to complete the same piece of work ? 
Options: a ) 15 min , b ) 30 min , c ) 26 min , d ) 28 min , e ) 18 min

Answer: b


Question: Problem: a train is 360 meter long is running at a speed of 30 km / hour . in what time will it pass a bridge of 140 meter length ? 
Options: a ) 87 , b ) 69 , c ) 60 , d ) 72 , e ) 21

Answer: c


Question: Problem: a crow leaves its nest , and flies back and forth from its nest to a nearby ditch to gather worms . the distance between the nest and the ditch is 100 meters . in one and a half hours , the crow manages to bring worms to its nest 15 times . what is the speed of the crow in kilometers per hour ? 
Options: a ) 1 , b ) 2 , c ) 3 , d ) 5 , e ) 7

Answer:
d