gwd上一道题，我觉得答案有误，求解~~~

sophiagregmat

If n is a positive integer, what is the value of the hundreds digit of 30ⁿ?

(1)30ⁿ > 1,000

(2)n is a multiple of 3.



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.
我选E,答案选D
n=1, 30ⁿ=30
n=2,  30ⁿ=900   百位9
n=3,  30ⁿ=2700 百位7
n=4,  30ⁿ=8100 百位1
n=5,  30ⁿ=24300 百位3
n=6, 30ⁿ=72900
然后4个一循环

Baodi

n=3  30的n次方是27000，百位是0,后面百位都是0，所以1，2都可以

sophiagregmat

谢谢~~how stupid I am!!! 深深感到我数学之差，连简单的计算都错了~~~