GWD-1-27-Math

henryest

Q26:

If the units digit of the three-digit positive integer k is nonzero, what is the tens digit of k?

(1)   The tens digit of k + 9 is 3.

(2)   The tens digit of k + 4 is 2.

                  

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.

answer is A. Why?

thanks

zhuxiaocao

1对吧。。。。2有些牵强了。。。

henryest

thought this problem has another meaning

1. the tens digit of (K+9) is 3

2.the tens digit of K, then this number +9 is 3.

Do you agree with me? If I meet this kind problem, usually which is perferable?

zhuxiaocao

(2)不行啊。124+4=128个位是2

              119+4=123个位也是2

henryest

What what's arong with (2)?

zhuxiaocao

个位数不是0，加上9以后十位数是3，那么K的个位数就肯定是2了。。