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'.

[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
[A]: a


[Q]: Problem: two taps a and b can fill a cistern in 12 minutes and 18 minutes respectively . they are turned on at the same time . if the tap a is turned off after 4 minutes , how long will tap b take to fill the rest of the cistern ? 
Options: a ) 8 min . , b ) 9 min . , c ) 10 min . , d ) 7 min . , e ) none of these
[A]: a


[Q]: Problem: the h . c . f . of two numbers is 12 and their l . c . m . is 600 . if one of the number is 120 , find the other ? 
Options: a ) 100 , b ) 60 , c ) 120 , d ) 200 , e ) 150
[A]:
b