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OG Square root of 16/81

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by Jay@ManhattanReview » Tue Jul 25, 2017 10:31 pm
AbeNeedsAnswers wrote:If n = (16/81)^(1/2), what is the value of n^(1/2)?

(A) 1/9
(B) 1/4
(C) 4/9
(D) 2/3
(E) 9/2

D
We have n = (16/81)^(1/2) = (4^2/9^2)^(1/2) = 4/9

n^(1/2) = (4/9)^(1/2)
n^(1/2) = (2^2/3^2)^(1/2) = [spoiler]2/3[/spoiler]

The correct answer: D

Hope this helps!

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by Jabs80 » Tue Jul 25, 2017 11:48 pm
AbeNeedsAnswers wrote:If n = (16/81)^(1/2), what is the value of n^(1/2)?

(A) 1/9
(B) 1/4
(C) 4/9
(D) 2/3
(E) 9/2

D
4/9
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by Jabs80 » Tue Jul 25, 2017 11:49 pm
Jabs80 wrote:
AbeNeedsAnswers wrote:If n = (16/81)^(1/2), what is the value of n^(1/2)?

(A) 1/9
(B) 1/4
(C) 4/9
(D) 2/3
(E) 9/2

D[/quote

2/3
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by DavidG@VeritasPrep » Wed Jul 26, 2017 4:11 am
Note also that when you take the root of a fraction between 0 and 1, the value of the fraction increases and moves closer to 1.
If n = 4/9, then √ (4/9) must be between 4/9 and 1. The only value in that range is 2/3. (Not that it's terribly difficult to find √ 4 and √ 9, but this property is helpful if you're given, say, √ .6.)
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by [email protected] » Wed Jul 26, 2017 6:58 pm
Jabs80 wrote:
AbeNeedsAnswers wrote:If n = (16/81)^(1/2), what is the value of n^(1/2)?

(A) 1/9
(B) 1/4
(C) 4/9
(D) 2/3
(E) 9/2

D
4/9
Hi Jabs80,

It looks like you caught your error, which is good. As you continue to study, you have to be mindful that the 4 wrong answers to any GMAT question are rarely 'random' - and some of those answers can be answers to DIFFERENT questions (so you have to be careful and make sure that you're answering the question that is ASKED). Here, while Answer C is the value of N, that is not what this question is asking for.

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by Scott@TargetTestPrep » Mon Aug 14, 2017 11:51 am
AbeNeedsAnswers wrote:If n = (16/81)^(1/2), what is the value of n^(1/2)?

(A) 1/9
(B) 1/4
(C) 4/9
(D) 2/3
(E) 9/2

D
We can simplify the given equation:

n = (16/81)^(1/2)

n = 4/9

Thus, n^(1/2) = 4/9^(1/2) = 2/3.

Answer: D

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by Matt@VeritasPrep » Fri Aug 18, 2017 2:14 pm
The half power is the same as the square root, so for legibility's sake let's write:

n = √16/81

n = 4/9

From here, √n = √4/9 = 2/3.
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by [email protected] » Mon Feb 19, 2018 8:27 pm
Hi All,

When taking the square root of a fraction, you must take the square root of the numerator and the square root of the denominator.

Here, the square root of 16/81 = 4/9

We're then asked to calculate the square root of 4/9.... and that would be 2/3

Final Answer: D

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