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: dan can do a job alone in 15 hours . annie , working alone , can do the same job in just 10 hours . if dan works alone for 3 hours and then stops , how many hours will it take annie , working alone , to complete the job ? 
Options: a ) 2 , b ) 4 , c ) 6 , d ) 8 , e ) 10
[EX A]: d

[EX Q]: Problem: if the product of two numbers is 45276 and their h . c . f . is 22 , find their l . c . m . 
Options: a ) 2574 , b ) 2500 , c ) 2100 , d ) 2058 , e ) none of these
[EX A]: d

[EX Q]: Problem: a certain number of men can do a work in 20 days . if there were 4 men less it could be finished in 5 days more . how many men are there ? 
Options: a ) 10 , b ) 20 , c ) 25 , d ) 30 , e ) 35
[EX A]:
b