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: how long does a train 165 meters long running at the rate of 54 kmph take to cross a bridge 660 meters in length ? 
Options: a ) 55 sec , b ) 40 sec , c ) 45 sec , d ) 30 sec , e ) 35 sec
[EX A]: a

[EX Q]: Problem: mike drives his new corvette from san francisco to las vegas , a journey of 640 miles . he drives the first half of the trip at an average rate of 80 miles per hour , but has to slow down for the second half of his journey . if the second half of the trip takes him 200 percent longer than the first half , what is his average rate j in miles per hour for the entire trip ? 
Options: a ) 26.7 , b ) j = 30.0 , c ) j = 40.0 , d ) j = 53.3 , e ) 60.0
[EX A]: c

[EX Q]: Problem: if there are 56 laborers in a crew , and on a certain day , 30 were present . calculate the percentage that showed up for work ? ( round to the nearest tenth ) . 
Options: a ) 53.6 % , b ) 52.6 % , c ) 54.6 % , d ) 55.6 % , e ) 59.6 %
[EX A]:
a