$$If\ \ 5\ge|x|\ge0$$ which of the following must be true?
$$I.\ x\ge0$$
$$II.\ \ x>-5$$
$$III.\ \ 25\ge x^2\ge-25$$
$$A.\ None$$
$$B.\ II\ only$$
$$C.\ III\ only$$
$$D.\ I\ and\ III\ only$$
$$E.\ II\ and\ III\ only$$
The OA is C.
Please, can any expert assist me with this PS question? I don't have it clear and I appreciate if any explain it for me. Thanks.
If 5 ≥ |x| ≥ 0, which of the following must be true?
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|x| = the distance between x and 0.AAPL wrote:$$If\ \ 5\ge|x|\ge0$$ which of the following must be true?
$$I.\ x\ge0$$
$$II.\ \ x>-5$$
$$III.\ \ 25\ge x^2\ge-25$$
$$A.\ None$$
$$B.\ II\ only$$
$$C.\ III\ only$$
$$D.\ I\ and\ III\ only$$
$$E.\ II\ and\ III\ only$$
|x| ≥ 0 implies that the distance between x and 0 must be greater than or equal to 0.
This will be true for any value of x.
5 ≥ |x| implies that the distance between x and 0 must be less than or equal to 5, as follows:
-5<---------->5.
Thus, 5 ≥ |x| ≥ 0 implies that x must be within the green range above.
Since it's possible that x=-5, Statements I and II do not have to be true.
Eliminate B, D and E.
The square of any value in the green range above will be between -25 and 25, inclusive.
Thus, Statement III must be true.
The correct answer is C.
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Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
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