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'.

[EX Q]: Problem: a man can row upstream at 26 kmph and downstream at 30 kmph , and then find the speed of the man in still water ? 
Options: a ) 29 , b ) 28 , c ) 30 , d ) 32 , e ) 23
[EX A]: b

[EX Q]: Problem: debony normally drives to work in 45 minutes at an average speed of 40 miles per hour . this week , however , she plans to bike to work along a route that decreases the total distance she usually travels when driving by 20 % . if debony averages between 12 and 16 miles per hour when biking , how many minutes earlier will she need to leave in the morning in order to ensure she arrives at work at the same time as when she drives ? 
Options: a ) 135 , b ) 105 , c ) 95 , d ) 75 , e ) 45
[EX A]: d

[EX Q]: Problem: in what time will a train 120 m long cross an electric pole , it its speed be 160 km / hr ? 
Options: a ) 2.5 sec , b ) 2.9 sec , c ) 2.7 sec , d ) 8.7 sec , e ) 8.5 sec
[EX A]:
c