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'.

Problem: on a race track a maximum of 5 horses can race together at a time . there are a total of 25 horses . there is no way of timing the races . what is the minimum number y of races we need to conduct to get the top 3 fastest horses ? 
Options: a ) 5 , b ) 7 , c ) 8 , d ) 10 , e ) 11
b

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
c

Problem: if 15 students in a class average 75 % on an exam and 10 students average 95 % on the same exam , what is the average in percent for all 25 students ? 
Options: a ) 81 % , b ) 82 % , c ) 83 % , d ) 84 % , e ) 85 %

c