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: if a and b are positive numbers , and a ^ 3 + b ^ 3 = 100 , then the greatest possible value of a is between : 
Options: a ) 0 and 3 , b ) 3 and 4 , c ) 4 and 5 , d ) 5 and 7 , e ) 7 and 9
c

Problem: find the value of 80641 x 9999 = m ? 
Options: a ) 807518799 , b ) 806436469 , c ) 807538799 , d ) 806329359 , e ) 817431046
d

Problem: x + ( 1 / x ) = 3 find x ^ 2 + ( 1 / x ^ 2 ) 
Options: a ) 2.25 , b ) 7 , c ) 4.25 , d ) 5.25 , e ) 6.25

b