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: of the final grades received by the students in a certain math course , 1 / 5 are a ' s , 1 / 4 are b ' s , 1 / 2 are c ' s , and the remaining 30 grades are d ' s . what is the number of students in the course ? 
Options: a ) 80 , b ) 110 , c ) 160 , d ) 600 , e ) 400
[A]: d


[Q]: Problem: what is the value of 8 1 / 3 % of 600 + 37 ½ of 400 
Options: a ) 100 , b ) 300 , c ) 150 , d ) 200 , e ) 250
[A]: d


[Q]: Problem: two kinds of vodka are mixed in the ratio 1 : 2 and 2 : 1 and they are sold fetching the profit 10 % and 30 % respectively . if the vodkas are mixed in equal ratio and the individual profit percent on them are increased by 4 / 3 and 5 / 3 times respectively , then the mixture will fetch the profit of 
Options: a ) 18 % , b ) 20 % , c ) 30 % , d ) 23 % , e ) can not be determined
[A]:
c