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Sub 505 Level|   Algebra|                     
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Bunuel
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 21 Oct 2015, 21:33
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D
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5% (low)

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94% (00:32) correct 6% (00:47) wrong based on 2692 sessions

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Is x = 1/y ?

(1) xy = 1
(2) 1/(xy) = 1
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D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 25 Oct 2020, 19:01
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Video solution from Quant Reasoning:
General Discussion
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 21 Oct 2015, 23:12
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Is x = 1/y ? --> Is x - (1/y) = 0 --> Is xy = 1 ?

St1: Sufficient
St2: (1/xy) - 1 = 0 --> 1 - xy = 0 --> xy = 1... Sufficient

Answer: D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 23 Oct 2015, 01:15
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Is x = 1/y?

(1) xy = 1
(2) 1/(xy) = 1

Kudos for a correct solution.

1) Rewrite to get x = 1/y --> sufficient
2) Multiply by x to get x = 1/y --> sufficient

Answer D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 23 Oct 2015, 20:41
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Is x = 1/y?

(1) xy = 1
(2) 1/(xy) = 1

From st 1
(1) xy = 1
there fore
x = 1/y

sufficient

From st 2
(2) 1/(xy) = 1

1/y = x ( simply rearranging the statement )

sufficient
hence D ans
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 18 Sep 2017, 02:26
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1 rewrite to get x=1/y sufficient
2 rewrite or multiply by x on both the sides you get x=1/y sufficient
D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 10 Oct 2017, 08:54
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Bunuel
Is x = 1/y?

(1) xy = 1
(2) 1/(xy) = 1

Kudos for a correct solution.

Target question: Is x = 1/y?

Statement 1: xy = 1
This tells us that y does NOT equal 0 (and x does NOT equal 0 too)
So, if we take xy = 1 and divide both sides by y, we get x = 1/y
PERFECT, this is exactly what we are looking for.
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: 1/(xy) = 1
This tells us that x and y do NOT equal 0
So, we can take 1/(xy) and multiply both sides by x to get 1/y = x
Also PERFECT!
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer:
Show Spoiler
D

Cheers,
Brent
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 11 Jan 2019, 03:05
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Cross multiply the question and it becomes xy = 1
Now check the options
So both separately prove xy=1
Hence D

Kudos please
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 31 May 2019, 05:07
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Is there any problem for multiplying or dividing any variables without knowing the sign?? I found it in the inequality problem and now get confused. Please suggest me when to consider this principle?
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 16 Sep 2019, 03:19
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Bunuel
Is x = 1/y?

(1) xy = 1
(2) 1/(xy) = 1

Kudos for a correct solution.

Is x = 1/y?

(1) xy = 1
x = 1/y
SUFFICIENT

(2) 1/(xy) = 1
x = 1/y
SUFFICIENT

IMO D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 16 Sep 2019, 04:43
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sajon
Is there any problem for multiplying or dividing any variables without knowing the sign?? I found it in the inequality problem and now get confused. Please suggest me when to consider this principle?

no - you just have to make sure you multiply both sides by the same thing.
There is a problem in inequalities - not in equations.
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 03 Nov 2020, 07:04
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BrentGMATPrepNow
Bunuel
Is x = 1/y?

(1) xy = 1
(2) 1/(xy) = 1

Kudos for a correct solution.

Target question: Is x = 1/y?

Statement 1: xy = 1
This tells us that y does NOT equal 0 (and x does NOT equal 0 too)
So, if we take xy = 1 and divide both sides by y, we get x = 1/y
PERFECT, this is exactly what we are looking for.
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: 1/(xy) = 1
This tells us that x and y do NOT equal 0
So, we can take 1/(xy) and multiply both sides by x to get 1/y = x
Also PERFECT!
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer:
Show Spoiler
D

Cheers,
Brent

Thank you Brent! Why does it matter than neither x nor y equal 0?
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 11 Nov 2020, 14:51
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Bunuel
Is x = 1/y ?

(1) xy = 1
(2) 1/(xy) = 1

As per me, OA should be E as both statement are tautological (simply restating what is asked)

Posted from my mobile device
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 11 Nov 2020, 14:55
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sushil8891
Bunuel
Is x = 1/y ?

(1) xy = 1
(2) 1/(xy) = 1

As per me, OA should be E as both statement are tautological (simply restating what is asked)

Posted from my mobile device

Yes, the statements are basically saying the same thing, but since each statement gives an YES answer to the question the answer is D, not E.
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 06 May 2021, 10:49
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Bunuel
Is x = 1/y ?

(1) xy = 1
(2) 1/(xy) = 1
Answer: Option D

Video solution by GMATinsight

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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 08 May 2021, 10:59
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Bunuel
Is x = 1/y ?

(1) xy = 1
(2) 1/(xy) = 1
Solution:

Question Stem Analysis:

We need to determine whether x = 1/y.

Statement One Alone:

Dividing both sides by y (since y can’t be 0), we have x = 1/y. Statement one alone is sufficient.

Statement Two Alone:

Multiplying both sides by xy (since xy can’t be 0), we have xy = 1. Since this is the same as statement one and statement one is sufficient, statement two is also sufficient.

Answer: D
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Is x = 1/y? (1) xy = 1 (2) 1/(xy) = 1 22 May 2024, 01:27
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