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

Problem: 120 + 520 ÷ 5.00 = ? 
Options: a ) 100 , b ) 150 , c ) 120 , d ) 520 , e ) none
e

Problem: solve for x and check : - 12 x = 72 
Options: a ) - 4 , b ) - 2 , c ) - 6 , d ) - 12 , e ) none of these

c