求教几个数学问题, 答案有疑问

sandyclause

1: If n is a positive integer, what is the remainder when 3^(8n+3) +2 is divdied by 5?
A. 0 B. 1 C. 2 D. 3 E.4
给的答案是A, 我觉得像是E 呢.......

2: A total of 100 customers purchased books at a certain bookstore last week. If these customers purchased a total of 200 books, how many of the customers purchased only 1book each?
(1) None of the customers purchased more than 3 books.
(2) 20 of the customers purchased only 2 books each.
给的答案是C, 我觉得是E

谢谢!!!!!!!!!!!!!!!!!!