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: what is the least whole number that should be added to 784839 if it is to be divisible by 10 ? 
Options: a ) 3 , b ) 2 , c ) 1 , d ) 5 , e ) 6
[EX A]: c

[EX Q]: Problem: a student chose a number , multiplied it by 8 , then subtracted 138 from the result and got 102 . what was the number he chose ? 
Options: a ) 30 , b ) 120 , c ) 130 , d ) 140 , e ) 150
[EX A]: a

[EX Q]: Problem: when n is divided by 15 , the remainder is 8 . what is the remainder when 5 n is divided by 6 ? 
Options: a ) 2 , b ) 6 , c ) 3 , d ) 4 , e ) 1
[EX A]:
d