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'.

Q: 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

A: d
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Q: Problem: cole drove from home to work at an average speed of 30 kmh . he then returned home at an average speed of 90 kmh . if the round trip took a total of 2 hours , how many minutes did it take cole to drive to work ? 
Options: a ) 66 , b ) 70 , c ) 72 , d ) 75 , e ) 90

A: e
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Q: Problem: a work as fast as b . if b can complete a work in 8 days independently , the number of days in which a and b can together finish the work in ? 
Options: a ) 2 days , b ) 2 2 / 3 days , c ) 4 days , d ) 5 days , e ) 6 days

A:
b
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