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: a high school has 400 students 1 / 2 attend the airthmetic club , 5 / 8 attend the biology club and 3 / 4 attend the chemistry club . 1 / 8 attend all 3 clubs . if every student attends at least one club how many students attend exactly 2 clubs . 
Options: a ) 300 , b ) 200 , c ) 250 , d ) 150 , e ) 160
c

Problem: solve the equation for x : 8 x - 40 + 2 x = 5 + 10 - x 
Options: a ) 4 , b ) 10 , c ) 7 , d ) 5 , e ) 3
d

Problem: in a certain school , 25 % of students are below 8 years of age . the number of students above 8 years of age is 2 / 3 of the number of students of 8 years of age which is 36 . what is the total number of students in the school ? 
Options: a ) 72 , b ) 80 , c ) 120 , d ) 150 , e ) 100

b