If a^2=b, is the value of a between 0 and 1?

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If a^2=b, is the value of a between 0 and 1? [#permalink]

01 Dec 2012, 00:37

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If a^2=b, is the value of a between 0 and 1?

(1) b is between 0 and 1
(2) a>b

[Reveal] Spoiler: OA

Last edited by Bunuel on 01 Dec 2012, 05:59, edited 1 time in total.

Edited the question.

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Re: If a*a=b, is the value of a between 0 and 1? [#permalink]

01 Dec 2012, 04:15

cv3t3l1na wrote:

If a*a=b, is the value of a between 0 and 1?
1. b is between 0 and 1
2. a>b

Why 2. is not sufficient?

Huh? Inside the spoiler you have given OA as B?

I guess both a sufficient by itself to answer to question "is the value of a between 0 and 1?"

Question rephrase ->a*a = b ; a^2 = b ; a = +/- \sqrt{b}
Is 0 < a < 1

Stat1/Given B is between 0 and 1.
a= 0.5 then b = 0.25 ; a is in between 0 and 1
a = -0.5 then b = 0.25 ; a is NOT between 0 and 1.
InSufficient

Stat2/ If a > b & a =\sqrt{b}only values that would satisfy these equations would be value from 0 to 1. Sufficient.

So D it is....

Cheers

Last edited by Jp27 on 01 Dec 2012, 07:23, edited 2 times in total.

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Re: If a*a=b, is the value of a between 0 and 1? [#permalink]

01 Dec 2012, 06:18

Jp27 wrote:

cv3t3l1na wrote:

If a*a=b, is the value of a between 0 and 1?
1. b is between 0 and 1
2. a>b

Why 2. is not sufficient?

Huh? Inside the spoiler you have given OA as B?

I guess both a sufficient by itself to answer to question "is the value of a between 0 and 1?"

Question rephrase ->a*a = b ; a^2 = b ; a = \sqrt{b}
Is 0 < a < 1

Stat1/ If B is between 0 and 1. Root of any value between 0 and 1 will result in a value larger than B but will still be fraction between 0 and 1. Sufficient

Stat2/ If a > b & a =\sqrt{b}only values that would satisfy these equations would be value from 0 to 1. Sufficient.

So D it is....

Cheers

If a = -0.5, b =0.25
a = 0.5 , b = 0.25 ...

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Re: If a*a=b, is the value of a between 0 and 1? [#permalink]

01 Dec 2012, 06:45

MacFauz wrote:

Jp27 wrote:

cv3t3l1na wrote:

If a*a=b, is the value of a between 0 and 1?
1. b is between 0 and 1
2. a>b

Why 2. is not sufficient?

If a = -0.5, b =0.25
a = 0.5 , b = 0.25 ...

Well MY reaction after reading your post :wall

....

I will edit my response...!

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Re: If a^2=b, is the value of a between 0 and 1? [#permalink]

01 Dec 2012, 06:54

If a^2=b, is the value of a between 0 and 1?

a^2=b --> a=-\sqrt{b} or a=\sqrt{b}.

(1) b is between 0 and 1. If b=\frac{1}{4}, then a could be -\frac{1}{2} (answer NO) or \frac{1}{2} (answer YES). Not sufficient.

(2) a>b --> a=\sqrt{b} --> 0<b<1. Sufficient.

Answer: B.
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Re: If a^2=b, is the value of a between 0 and 1? [#permalink] 01 Dec 2012, 06:54

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If a^2=b, is the value of a between 0 and 1?

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If a^2=b, is the value of a between 0 and 1?

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