If n is an integer between 100 and 900

[DianaN928]

I understand why #1 is sufficient based off the explanation provided on the CAT, but I don't understand why #2 is INSUFFICENT.

Below (in bold) is the reasoning provided as to WHY #2 is insufficient. I can't see how the hundreds digit times 2 equals the tens digit. Uh, 4x2=2? 8x2=4? This doesn't make sense to me.

I can ONLY see how the tens digit times 2 equals the units digit. For example, 2x2 = 4. 4x2 = 8.

(2) INSUFFICIENT: According to this statement, the hundreds digit times 2 equals the tens digit, and the tens digit times 2 equals the units digit. This statement yields two possibilities, n = 124 and n = 248. These two values of n have different tens digits, so the statement is not sufficient.



CAT Question:
If n is an integer between 100 and 900, what is the tens digit of n?
 
(1) If n is rounded to the nearest ten and the result is then rounded to the nearest hundred, the final value differs from the result of rounding n to the nearest hundred.
 
(2) The tens digit of n is half the units digit of n and is twice the hundreds digit of n.


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 one ALONE is sufficient.


EACH statement ALONE is sufficient.


Statements (1) and (2) TOGETHER are NOT sufficient.

[Sage Pearce-Higgins]

I'm not sure I see your problem here. Let's look at that second statement:

(2) The tens digit of n is half the units digit of n and is twice the hundreds digit of n.

Take the number 124. The tens digit is 2, which is half the units digit (4) and twice the hundreds digit (1).
Alternatively, take the number 248. The tens digit is 4, which is half the units digit (8) and twice the hundreds digit (2).

Confusingly worded, I know.