Absolute value Ques. Need help..plz

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Absolute value Ques. Need help..plz

by pardeep_10sharma » Sun May 16, 2010 12:27 am
What is the value of mode x+7 ?
(1) mode x+3 = 14
(2) (x + 2)^2 = 169

Ans which is given at end is:- D but i am getting C. Plz confirm which is correct

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by Stuart@KaplanGMAT » Sun May 16, 2010 9:17 am
pardeep_10sharma wrote:What is the value of mode x+7 ?
(1) mode x+3 = 14
(2) (x + 2)^2 = 169

Ans which is given at end is:- D but i am getting C. Plz confirm which is correct
Hi,

C is definitely correct, since each statement gives two values for x and, accordingly, 2 values for |x+7|.

Please post the source of every question that you ask about - that way we can easier judge whether there's likely to be an error and people know which sources are untrustworthy.

Showing the work:

Q: what's the value of |x+7|?

(1) |x+3| = 14

+(x+3) = 14 or -(x+3) = 14
x = 11 or x = -17

If x=11, then |x+7| = 18
If x = -17, then |x + 7| = 10

(2) (x+2)^2 = 169

x+2 = 13 or x+2 = -13
x = 11 or x = -15

If x=11, then |x+7| = 18
If x = -15, then |x+7|= -8

Combined: only x=11 fits both... sufficient, choose (C).
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