2 jj want to confirm

loulan

DS
K is a three digit integer, whose unit digit is not zero.  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
Answer C.

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my answer is A,

3. apts, 45% have residents 3 or fewer, what is median of the residents?
1)80% have 5 or fewer
2)35% have 3 or more.
answer E

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I think answer should be D

cook

Oh....., Got it. You are right, tongxun!

tongxun

是第一题吧，xulingyan？
K is a three digit integer, whose unit digit is not zero. 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
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K 是一个3位数的整数，它的个位不是0，它的十位是什么？
两个条件给出的都是，K + 某个数字后的十位数。
即：K+9的十位数等于3，可知K的十位等于2。
   K+4的十位等于2， 这就会有两种情况：K的个位小于等于5，或大于5。

xulingyan

请哪位用中文解释一下好吗？

cook

NO, you see, it ask the tens digit +9 or 4, -->D

tongxun

cook: why the answer is D?
if k =124, then K +4=128, the tens is 2. if k=118, then 118+4=122, the tens of the sum is 2 too.
so the right answer is A

cook

What do those mean?
(1) The tens digit of K + 9 is 3
(2) The tens digit of K + 4 is 2

according literal meaning, the answer should be D .

tongxun

2. A.  k+9 and k is not equal to 0, the tens must be 2.
       condition 2: the tens maybe 1 or 2.
3. E.  condition 1: the median may be 4 or 5.
       condition 2 is insufficient too.