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# In which of the following pairs are the two numbers reciproc

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Re: In which of the following pairs are the two numbers reciproc [#permalink]
1
Kudos
In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3
II. 1/17 and -1/17
III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

(A) I only
(B) II only
(C) I and II
(D) I and III
(E) II and III

Reciprocal for a number $$x$$, denoted by $$\frac{1}{x}$$ or $$x^{-1}$$, is a number which when multiplied by $$x$$ yields $$1$$. The reciprocal of a fraction $$\frac{a}{b}$$ is $$\frac{b}{a}$$. To get the reciprocal of a number, divide 1 by the number. For example reciprocal of $$3$$ is $$\frac{1}{3}$$, reciprocal of $$\frac{5}{6}$$ is $$\frac{6}{5}$$.

Reciprocal of 3 is 1/3.

Reciprocal of 1/17 is 17. Discard.

Reciprocal of $$\sqrt{3}$$ is $$\frac{1}{\sqrt{3}}=\frac{\sqrt{3}}{3}$$.

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Re: In which of the following pairs are the two numbers reciproc [#permalink]
2
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Bunuel wrote:
In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3
II. 1/17 and -1/17
III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

(A) I only
(B) II only
(C) I and II
(D) I and III
(E) II and III

Reciprocal for a number $$x$$, denoted by $$\frac{1}{x}$$ or $$x^{-1}$$, is a number which when multiplied by $$x$$ yields $$1$$. The reciprocal of a fraction $$\frac{a}{b}$$ is $$\frac{b}{a}$$. To get the reciprocal of a number, divide 1 by the number. For example reciprocal of $$3$$ is $$\frac{1}{3}$$, reciprocal of $$\frac{5}{6}$$ is $$\frac{6}{5}$$.

Reciprocal of 3 is 1/3.

Reciprocal of 1/17 is 17. Discard.

Reciprocal of $$\sqrt{3}$$ is $$\frac{1}{\sqrt{3}}=\frac{\sqrt{3}}{3}$$.

Hi Bunuel,

We need reciprocals of given number so for 3 it will be 1/3 and for \sqrt{3} it will be 1/ \sqrt{3} or \sqrt{3}/3.

Ans should be D.

For II is not a reciprocal, reciprocal of 1/17 is 17
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
WoundedTiger wrote:
Bunuel wrote:
In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3
II. 1/17 and -1/17
III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

(A) I only
(B) II only
(C) I and II
(D) I and III
(E) II and III

Reciprocal for a number $$x$$, denoted by $$\frac{1}{x}$$ or $$x^{-1}$$, is a number which when multiplied by $$x$$ yields $$1$$. The reciprocal of a fraction $$\frac{a}{b}$$ is $$\frac{b}{a}$$. To get the reciprocal of a number, divide 1 by the number. For example reciprocal of $$3$$ is $$\frac{1}{3}$$, reciprocal of $$\frac{5}{6}$$ is $$\frac{6}{5}$$.

Reciprocal of 3 is 1/3.

Reciprocal of 1/17 is 17. Discard.

Reciprocal of $$\sqrt{3}$$ is $$\frac{1}{\sqrt{3}}=\frac{\sqrt{3}}{3}$$.

Hi Bunuel,

We need reciprocals of given number so for 3 it will be 1/3 and for \sqrt{3} it will be 1/ \sqrt{3} or \sqrt{3}/3.

Ans should be D.

For II is not a reciprocal, reciprocal of 1/17 is 17

Yes, I and III is D, not E. Typo edited. Thank you.
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
easy question.. wish all GMAT could be this simple
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
3
Kudos
In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3

Reciprocal of $$3 = \frac{1}{3}$$

I - TRUE

II. 1/17 and -1/17

Reciprocal of $$\frac{1}{17}$$ is $$17$$

II - FALSE

III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

Reciprocal of $$\sqrt{3}$$ $$= \frac{1}{\sqrt{3}}$$

Multiply and divide the above equation by $$\sqrt{3}$$, we get

$$\frac{\sqrt{3}}{3}$$

III - TRUE

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Re: In which of the following pairs are the two numbers reciproc [#permalink]
Bunuel wrote:
The Official Guide For GMAT® Quantitative Review, 2ND Edition

In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3
II. 1/17 and -1/17
III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

(A) I only
(B) II only
(C) I and II
(D) I and III
(E) II and III

Problem Solving
Question: 8
Category: Arithmetic Properties of numbers (reciprocals)
Page: 63
Difficulty: 600

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It is a very easy question and can be solved within 20 seconds.
We can see 3 and 1/3 are reciprocals of each other.
Reciprocal of 1/17 is 17 and not -1/17

Reciprocal of $$\sqrt{3}$$ is $$\frac{1}{\sqrt{3}}$$ = $$\frac{\sqrt{3}}{3}$$

So, I & III is correct and Hence option D
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
1
Kudos
Can someone please tell me how 1/sqr3 is equal to sqr3/3? Thanks!

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Re: In which of the following pairs are the two numbers reciproc [#permalink]
ydmuley wrote:
In which of the following pairs are the two numbers reciprocals of each other?

I. 3 and 1/3

Reciprocal of $$3 = \frac{1}{3}$$

I - TRUE

II. 1/17 and -1/17

Reciprocal of $$\frac{1}{17}$$ is $$17$$

II - FALSE

III. $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{3}$$

Reciprocal of $$\sqrt{3}$$ $$= \frac{1}{\sqrt{3}}$$

Multiply and divide the above equation by $$\sqrt{3}$$, we get

$$\frac{\sqrt{3}}{3}$$

III - TRUE

Can you please tell me how you got $$\frac{\sqrt{3}}{3}$$ from 1/sqr3
Why did you multiple and divide?
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
1
Bookmarks
D is the right answer. I think the level of question is in the 300's.
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
1
Kudos
Option I: 3 and 1/3 are reciprocal of each other.

Option II: 1/17 and -1/17 are not reciprocal of each other.

Option III: $$\sqrt{3}$$ and $$\frac{\sqrt{3}}{ 3}$$

=> $$\frac{\sqrt{3}}{ 3}$$ = $$\frac{\sqrt{3}}{ (\sqrt{3} * \sqrt{3})}$$ = $$\frac{1}{ \sqrt{3}}$$

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Re: In which of the following pairs are the two numbers reciproc [#permalink]
Reciprocals means x * (1/x) = 1 i.e The reciprocal or multiplicative inverse of a number x is the number which, when multiplied by x , gives 1

Going by the options:
1. 3*(1/3) = 1 -- true
2. 17*(-1/17) = -1 -- not true
3. sqrt(3) * (sqrt(3)/3) = 3/3 = 1 -- true

So only 1st and 3rd options are correct.
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
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Re: In which of the following pairs are the two numbers reciproc [#permalink]
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