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'.

[EX Q]: Problem: 123 : 36 : : 221 : ? 
Options: a ) 52 , b ) 69 , c ) 72 , d ) 25 , e ) 32
[EX A]: d

[EX Q]: Problem: 0.002 x 0.6 = ? 
Options: a ) 0.0012 , b ) 0.001 , c ) 0.01 , d ) 0.1 , e ) none of these
[EX A]: a

[EX Q]: Problem: for each month of a given year except december , a worker earned the same monthly salary and donated one - tenth of that salary to charity . in december , the worker earned n times his usual monthly salary and donated one - fifth of his earnings to charity . if the worker ' s charitable contributions totaled one - seventh of his earnings for the entire year , what is the value of n ? 
Options: a ) 31 / 4 , b ) 33 / 4 , c ) 29 / 4 , d ) 27 / 4 , e ) 25 / 4
[EX A]:
b