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'.

[Q]: Problem: how many 3 - digit positive integers are there , where each digit is positive , and no 3 adjacent digits are same ?
Options: a ) 1236 , b ) 504 , c ) 4096 , d ) 4608 , e ) 6561
[A]: b

[Q]: Problem: a certain manufacturer produces items for which the production costs consist of annual fixed costs totaling $ 130,000 and variables costs averaging $ 5 per item . if the manufacturer ' s selling price per item is $ 15 , how many items the manufacturer produce and sell to earn an annual profit of $ 150,000 ?
Options: a ) 2,858 , b ) 18,667 , c ) 28,000 , d ) 35,000 , e ) 40,000
[A]: c

[Q]: Problem: the sum of the even numbers between 1 and k is 79 * 80 , where k is an odd number , then k =
Options: a ) 79 , b ) 80 , c ) 81 , d ) 157 , e ) 159
[A]:
e