In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Q: Problem: 3 times the first of 3 consecutive odd integers is 3 more than twice the third . the third integer is ? 
Options: a ) 15 , b ) 17 , c ) 19 , d ) 21 , e ) 26

A: a
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Q: Problem: it takes 30 days to fill a laboratory dish with bacteria . if the size of the bacteria doubles each day , how long did it take for the bacteria to fill one sixteenth of the dish ? 
Options: a ) 16 days , b ) 26 days , c ) 27 days , d ) 28 days , e ) 29 days

A: b
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Q: Problem: mid intended to type a 7 - digit number , but the two 3 ' s he meant to type did not appear . what appeared instead was the 5 - digit number 52115 . how many different 7 - digit numbers could mid have meant to type ? 
Options: a ) 10 , b ) 16 , c ) 21 , d ) 24 , e ) 27

A:
c
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