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'.

[EX Q]: Problem: the “ a - number ” of a number x is defined as the ones digit of 2 ^ x . antony rolls a die with 6 sides labeled with the integers from 1 to 6 , each of which has an equal probability of landing face - up . he then takes 3 ^ a , where a is the a - number of the result of his die roll , and plots 3 ^ a on a number line as the point a . finally , he repeats this entire process , this time plotting the result as the point b . what is the probability that the distance between a and b is greater than the value of b ? 
Options: a ) 3 / 8 , b ) 13 / 36 , c ) 17 / 36 , d ) 19 / 36 , e ) 23 / 36
[EX A]: b

[EX Q]: Problem: 54671 - 14456 - 35466 = ? 
Options: a ) 2449 , b ) 5449 , c ) 6749 , d ) 6449 , e ) 4749
[EX A]: e

[EX Q]: Problem: when 1 / 10 percent of 7000 is subtracted from 1 / 10 of 7000 , the difference is 
Options: a ) 0 , b ) 50 , c ) 450 , d ) 693 , e ) 500
[EX A]:
d