What is the value of w^(2)? (1) w^(1) = 1/2 (2) w^3 = 8

Question

What is the value of w^(−2)?

(1) w^(−1) = 1/2
(2) w^3 = 8

Skywalker18 · Answer

1. w^(-1)=(1/2)
=> (w^(-1))^2 =(1/2)^2
 =1/4

Sufficient

2. w^3 =8
=> w= 2
=>w^(-2)=1/(w^2)= 1/4

Sufficient
Answer D

reto · Answer

Rewrite the question to what is the value of  \frac{1}{w^2}

1) 1/w = 1/2, hence w = 2, sufficient
2) w^3 = 8, hence w = 2 or -2, sufficient since w^2 will always be positive

Answer D

TheKingInTheNorth · Answer

What is the value of w^(−2)?

(1) w^(−1) = 1/2
(2) w^3 = 8

effectively we need to calculate 1/(w)^2
there fore we need to know w ?

1. w^(−1) = 1/2
1/w= 1/2
hence w =2 
Since we got unique value .we can calculate 1/(w)^2

2.w^3 = 8
hence w =2 
Again we got unique value .we can calculate 1/(w)^2

Hence D ans

GMATinsight · Answer

Question : What is the value of w^(−2) ot 1/w^2?

Statement 1 : w^(−1) = 1/2 
i.e. 1/w = 1/2
i.e. 1/w^2 = 1/4
SUFFICIENT

Statement 2 : w^3 = 8 
i.e. w = 2
i.e. 1/w^2 = 1/4
SUFFICIENT

Answer Option D

ThisandThat · Answer

If either statement 1 or 2 gave us an even power, would it still be sufficient?

i.e. if statement 1 was: W^-2 = number or W^2 = number
would that still be sufficient?

Bunuel · Answer

Yes, because we want to find 1/w^2 and we could simply substitute the value of w^2 there without solving for w.

Nups1324 · Answer

Hi Bunuel , Just a small doubt regarding negative power. To change the negative power of w^(-1) we simply take the reciprocal and the power becomes positive. But we don't take the reciprocal of the RHS (in this case) w^(-1)=1/2 doesn't become 1/w^1=2..right..? Tagging others just in case Bunuel is busy or goes offline. yashikaaggarwal chetan2u GMATinsight IanStewart Thank you.

Posted from my mobile device

GMATinsight · Answer

Nups1324 The rule of exponents is a^{-x} = \frac{1}{a^x} i.e. w^{-1} = \frac{1}{w^2} = 1/2 ie.. w = 2 I hope this help!

chetan2u · Answer

Yes, you will take the reciprocal of whatever you want to change the sign of power of. 
1/2=2^(-1)
And w^(-1)=1/w

avigutman · Answer

Video solution from Quant Reasoning: Subscribe for more: https://www.youtube.com/QuantReasoning? ... irmation=1 https://www.youtube.com/watch?v=uzIrYSPMreY

GMATinsight · Answer

Answer: Option D

Video solution by  GMATinsight

https://www.youtube.com/watch?v=r_zWvDR6SHI

ScottTargetTestPrep · Answer

Solution:
 
 Question Stem Analysis:
 
We need to determine the value of w^(-2).

Statement One Alone:

Since w^(-2) =  ^2 and w^(-1) = 1/2, w^(-2) =  ^2 = 1/4. Statement one alone is sufficient.

Statement Two Alone:

Since w^3 = 8, w = ∛8 = 2. So w^(-2) = 2^(-2) = 1/4. Statement two alone is sufficient.

Answer: D

bumpbot · Answer

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What is the value of w^(2)? (1) w^(1) = 1/2 (2) w^3 = 8

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