If the terms of a sequence are t1, t2, t3, . . . , tn, what is the value of n ?
(1) The sum of the n terms is 3,124.
(2) The average (arithmetic mean) of the n terms is 4.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
The sum of the n terms是指数列的和,不是1,2,3...n的和
登录 或 注册 后可以参加讨论