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: if x + ( 1 / x ) = 5 , what is the value of w = x ^ 2 + ( 1 / x ) ^ 2 ? 
Options: a ) w = 21 , b ) w = 22 , c ) w = 23 , d ) w = 24 , e ) 27

A: c
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Q: Problem: what is the average of first 21 multiples of 5 ? 
Options: a ) a ) 70 , b ) b ) 77 , c ) c ) 55 , d ) d ) 81 , e ) e ) 82

A: c
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Q: Problem: for a group of n people , k of whom are of the same sex , the ( n - k ) / n expression yields an index for a certain phenomenon in group dynamics for members of that sex . for a group that consists of 20 people , 8 of whom are females , by how much does the index for the females exceed the index for the males in the group ? 
Options: a ) 0.05 , b ) 0.0625 , c ) 0.2 , d ) 0.25 , e ) 0.6

A:
c
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