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: due to construction , the speed limit along an 7 - mile section of highway is reduced from 55 miles per hour to 35 miles per hour . approximately how many minutes more will it take to travel along this section of highway at the new speed limit than it would have taken at the old speed limit ? 
Options: a ) 2 , b ) 3 , c ) 4 , d ) 5 , e ) 6

A: c
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Q: Problem: a man rows his boat 75 km downstream and 45 km upstream , taking 2 1 / 2 hours each time . find the speed of the stream ? 
Options: a ) 6 , b ) 7 , c ) 5 , d ) 8 , e ) 9

A: a
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Q: Problem: a farming field can be ploughed by 6 tractors in 4 days . when 6 tractors work together , each of them ploughs 120 hectares a day . if two of the tractors were moved to another field , then the remaining 4 tractors could plough the same field in 5 days . how many hectares a day would one tractor plough then ? 
Options: a ) 144 , b ) 255 , c ) 148 , d ) 265 , e ) 320

A:
a
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