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: an electric pump can fill a tank in 6 hours . because of a leak in the tank , it took 12 hours to fill the tank . if the tank is full , how much time will the leak take to empty it ? 
Options: a ) 10 hours , b ) 12 hours , c ) 8 hours , d ) 5 hours , e ) 15 hours

A: b
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Q: Problem: an intern wants to label folders with numbers using digit stickers only . if the intern uses 999 stickers , how many folders have been numbered ? ( the numbers of the folders are consecutive and the number of the first folder is 1 ) . 
Options: a ) 287 , b ) 369 , c ) 370 , d ) 371 , e ) 430

A: b
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Q: Problem: a is thrice as good a work man as b and together they finish a piece of work in 12 days . the number of days taken by a alone to finish the work is : 
Options: a ) 28 days . , b ) 14 days . , c ) 12 days . , d ) 16 days . , e ) 18 days .

A:
d
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