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# What is the value of x + 7 ? (1) x + 3 = 14 (2) (x + 2)^2 =

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What is the value of x + 7 ? (1) x + 3 = 14 (2) (x + 2)^2 = [#permalink]  18 Aug 2010, 01:49
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6% (01:05) correct 93% (00:32) wrong based on 15 sessions
What is the value of │x + 7│?
(1) │x + 3│= 14
(2) (x + 2)^2 = 169
[Reveal] Spoiler: OA
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Re: Is OA Wrong?? [#permalink]  18 Aug 2010, 02:38
amitjash wrote:
What is the value of │x + 7│?
(1) │x + 3│= 14
(2) (x + 2)^2 = 169

I guess you are right it should be C not D,

From both the statements we get 2 values but combining 1 and 2 we get x=11.

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Re: Is OA Wrong?? [#permalink]  18 Aug 2010, 12:43

A. gives us two values of x i.e. x = 11 or x = -11. However when you substitute these values back into equation given in A, x = 11 is the only valid value. Hence we can find mod ( x + 7 ) = 18

Hence A sufficient.

B. also gives us two values of x, i.e. 11 and -11. Resubstitute both values and validate the equation given in B. It holds true only for x = 11. Hence we are able to find mod (x + 7).

Hence B is sufficient as well.

Hence D is correct answer. Thank You.

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Akhil M.Parekh
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Re: Is OA Wrong?? [#permalink]  18 Aug 2010, 19:14
amp0201 wrote:

A. gives us two values of x i.e. x = 11 or x = -11. However when you substitute these values back into equation given in A, x = 11 is the only valid value. Hence we can find mod ( x + 7 ) = 18

Hence A sufficient.

B. also gives us two values of x, i.e. 11 and -11. Resubstitute both values and validate the equation given in B. It holds true only for x = 11. Hence we are able to find mod (x + 7).

Hence B is sufficient as well.

Hence D is correct answer. Thank You.

Thanks,
Akhil M.Parekh

B gives 2 values as 11 and -15

(x+2)^2= 13 ^2

(x+2)=+-13

x=11 , -15

Hence 2 different values

Can you explain how did you get values as 11 and -11 in statement B?
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Re: Is OA Wrong?? [#permalink]  18 Aug 2010, 21:15
amp0201 wrote:

A. gives us two values of x i.e. x = 11 or x = -11. However when you substitute these values back into equation given in A, x = 11 is the only valid value. Hence we can find mod ( x + 7 ) = 18

Hence A sufficient.

B. also gives us two values of x, i.e. 11 and -11. Resubstitute both values and validate the equation given in B. It holds true only for x = 11. Hence we are able to find mod (x + 7).

Hence B is sufficient as well.

Hence D is correct answer. Thank You.

Thanks,
Akhil M.Parekh

I think its C.

1) This raises two values, X=11 and -17. Therefore, insufficient.
2) This again raises to two values, X=11 and -15. Therefore, insufficient.

Considering 1 and 2, the common value X=11 is considered. Therefore, sufficient.
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Re: Is OA Wrong?? [#permalink]  18 Aug 2010, 22:11
Sorry my bad. Yes I calculated it wrong.

For B - it is 11 and -15. Hence insufficient.

Together A and B -> x = 11. Hence C is correct answer.

Thanks for pointing out the mistake.

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Re: Is OA Wrong?? [#permalink]  03 Sep 2010, 10:40

Statement (1) gives two values, x = 11, and x = -17. Both of these values adequately satisfy the equation |x+3|=14. Plug them into |x+7| to get |11+7|=18 and |-17+7|=10. Two different values, thus we can't determine a single solution for x.

Statement (2) also gives two values, x = 11 and x = -15. Both of these values satisfy the equation (x+2)^2=169. Plug them into |x+7| to get |11+7|=18 and |-15+7|=8. Two different values again, thus we can't determine a single solution for x.

Combine (1) and (2) to get x = 11, which results in a single value for |x+7|.
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Re: Is OA Wrong?? [#permalink]  03 Sep 2010, 11:08
IMO is C but requesting BL to confirm this.
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Re: Is OA Wrong?? [#permalink]  03 Sep 2010, 11:23
answer should be C as for
1) we have two solutions -- 11 & -17
2)we have two answers -- -15,11
but when we combine both of them we have one answer that is to be 11
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Inequality - wrong OA [#permalink]  03 Sep 2010, 23:37
I think D is wrong. What do you think ?
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Re: Inequality - wrong OA [#permalink]  04 Sep 2010, 01:22
nusmavrik wrote:
I think D is wrong. What do you think ?

Yep, OA is wrong here.

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Re: Inequality - wrong OA [#permalink]  09 Sep 2010, 11:43
I believe C is the answer......
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Re: Inequality - wrong OA [#permalink]  09 Sep 2010, 11:47
What is the value of │x + 7│?
(1) │x + 3│= 14
(2) (x + 2)2 = 169

Yes, OA must be wrong here.

(1) |x+3|=14 --> x=11 or x=-17, so |x+7|=18 or |x+7|=10;
(2) (x+2)^2=169 --> x=11 or x=-15, so |x+7|=18 or |x+7|=8;

(1)+(2) |x+7|=18. Sufficient.

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Re: Inequality - wrong OA [#permalink]  09 Sep 2010, 15:54
OA can be correct if question has some more info. Like if x > 0 then D is possible answer
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Re: Inequality - wrong OA   [#permalink] 09 Sep 2010, 15:54
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