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: twelve machines , each working at the same constant rate , together can complete a certain job in 6 days . how many additional machines , each working at the same constant rate , will be needed to complete the job in 3 days ? 
Options: a ) 14 , b ) 12 , c ) 15 , d ) 16 , e ) 18
[EX A]: b

[EX Q]: Problem: a boat m leaves shore a and at the same time boat b leaves shore b . they move across the river . they met at 500 yards away from a and after that they met 300 yards away from shore b without halting at shores . find the distance between the shore a & b 
Options: a ) 1000 yards , b ) 1200 yards , c ) 1400 yards , d ) 1600 yards , e ) 1800 yards
[EX A]: b

[EX Q]: Problem: the length of the bridge , which a train 150 meters long and travelling at 45 km / hr can cross in 30 seconds , is : 
Options: a ) 230 , b ) 225 , c ) 245 , d ) 238 , e ) 236
[EX A]:
b