Practice question

[Ned Batchelder]

On 10/5/14 8:07 PM, Seymore4Head wrote:
> On Sun, 05 Oct 2014 19:14:27 -0400, Ned Batchelder
> <ned at nedbatchelder.com> wrote:
>
>> On 10/5/14 7:02 PM, Seymore4Head wrote:
>>> For the record, I don't want a hint.  I want the answer.
>>> I see a practice question is similar to this.
>>> 15 <= x < 30  And it wants a similar expression that is equivalent.
>>> So the right answer is 15<= x or x <30
>>
>> No, "15 <= x < 30" is equivalent to "15 <= x and x < 30".
>>
>>> but one of the other answers is
>>> not (15<= x and x <30)
>>
>> You are speaking ambiguously.  Which did you mean:
>> a) one of the other answers isn't "15 <= x and x < 30", or:
>> b) one of the other answers is "not (15 <= x and x < 30)" ?
>
> Here is the exact question, I was trying to post something similar.  I
> failed.
>
> http://i.imgur.com/iUGh4xf.jpg
>

Why isn't the fourth one correct?

-- 
Ned Batchelder, http://nedbatchelder.com