Let S be the set of all positive integers that, when divided by 8, have a remainder of 5. What is the 81th number in this set?	Choose one:
A) 605 B) 608 C) 613 D) 616 E) 645

Rationale: "the set s = { 5 , 13 , 21 , 29 , . . . . . . . . . . . . . . . . . . . . . } 1 st number = 8 * 0 + 5 = 5 2 nd number = 8 * 1 + 5 = 13 3 rd number = 8 * 2 + 5 = 21 81 th number = 8 * ( 81 - 1 ) + 5 = 645 answer = e"
Answer: E