Q15: The average (arithmetic mean) of a list of numbers is what percent of the sum of the numbers? (1) There are 8 numbers in the list. (2) The sum of the numbers in the list is 100. A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient. B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient. C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient. D. EACH statement ALONE is sufficient. E. Statements (1) and (2) TOGETHER are NOT sufficient. 答案是A，怎么有理由呢？ | 
