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 car drives 90 miles on local roads at 30 mph , and 75 miles on the highway at 60 mph , what is the average speed of the entire trip ? 
Options: a ) 36 mph , b ) 40 mph , c ) 39 mph , d ) 42 mph , e ) 38 mph
[EX A]: c

[EX Q]: Problem: today mary ’ s father is 4 times as old as mary . 3 years ago , he was 5 times as old . how old is mary today ? 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 14
[EX A]: d

[EX Q]: Problem: in what time will a train 100 m long cross an electric pole , it its speed be 90 km / hr ? 
Options: a ) 2.5 , b ) 2.9 , c ) 4 sec , d ) 2.8 , e ) 2.1
[EX A]:
c