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: it takes 35 identical printing presses 12 hours to print 500,000 papers . how many hours would it take 30 of these printing presses to print 500,000 papers ? 
Options: a ) 14 , b ) 15 , c ) 16 , d ) 18 , e ) 20
[EX A]: a

[EX Q]: Problem: a garrison of 2000 men has provisions for 54 days . at the end of 15 days , a reinforcement arrives , and it is now found that the provisions will last only for 30 days more . what is the reinforcement ? 
Options: a ) 1800 men , b ) 3900 men , c ) 600 men , d ) 3800 men , e ) 900 men
[EX A]: c

[EX Q]: Problem: two trains running in opposite directions cross a man standing on the platform in 47 seconds and 38 seconds respectively and they cross each other in 40 seconds . the ratio of their speeds is : 
Options: a ) 3 : 1 , b ) 3 : 2 , c ) 2 : 7 , d ) 3 : 25 , e ) 3 : 4
[EX A]:
c