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Rick can solve x algebra problems per minute. Matt can solve y calculu

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Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 04 Feb 2015, 08:45
1
4
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

63% (01:54) correct 37% (01:35) wrong based on 304 sessions

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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 04 Feb 2015, 09:52
1
Statement 1: x > 3 does not give any information on y and x could be an infinite number of values
Statement 2: dividing by a negative value in an inequality reverses the sign so if we divide both sides of the inequality by -1 then -(x/y) < 3 becomes (x/y) > 3 which is sufficient to answer the question.

The correct answer is B.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 05 Feb 2015, 21:19
2
Doesn't it become x/y>-3?
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 05 Feb 2015, 21:48
1
R=x/min, so x>=0 and integer
M=y/min, so y>0 and integer
Question: Is x/y>3 or x more than three times more than y? Yes/No question

St.1. x>0. No information about y. INSUFF

St.2. -(x/y)<3 => x/y>-3 means that x/y can be 0,1,2,3 or >3. INSUFF

St.1+St.2. Just exclude x/y=0 but still makes 1,2,3 or >3 possible. INSUFF

E
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 05 Feb 2015, 23:06
1
Here we go:

y is not equal to zero (given)

St1: x > 3

No information is given for Y.

Clearly Insufficient.

St2: –(x/y) < 3

x/y > -3

x = 1, y = 1 (x/y > -3, but x/y is not > 3)

x = 8, y = 2 (x/y > -3, and x/y > 3)

Two solutions possible..
Clearly Insufficient.

Combining

We are talking in terms of efficiency of X and Y.

Take x = 4 and Y = 3 (x/y is not > 3)
Take x = 4 and Y = 1 (x/y > 3)

Two possible solutions.

Clearly E is the answer.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 05 Feb 2015, 23:39
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Hi All,

Certain DS questions on the Official GMAT will include a "redundant" piece of information in one (or both) of the two Facts. By 'redundant', I mean that it is information that was either already given in the prompt (or something that you can deduce from the information in the prompt). Redundant Facts are always insufficient (since you already had the information, the Fact does not offer anything new).

Here, we're told that Rick can solve X problems per minute and Matt can solve Y problems per minute. Neither of these 2 variables can be negative (a person cannot solve "negative" problems in the context of this question). We're also told that Y CANNOT be 0. As such, X/Y is either 0 or it's positive, so the information that -(X/Y) < 3 is redundant, since -(X/Y) is either 0 or it's negative and ALL of those possibilities are LESS than +3. Thus, Fact 2 is INSUFFICIENT.

While redundant information isn't that common on the Official GMAT, you'll likely have to deal with it at least once, so it's important to take the proper notes and make whatever deductions you can with the information that appears in the prompt.

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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 06 Feb 2015, 00:17
EMPOWERgmatRichC wrote:
Hi All,

Certain DS questions on the Official GMAT will include a "redundant" piece of information in one (or both) of the two Facts. By 'redundant', I mean that it is information that was either already given in the prompt (or something that you can deduce from the information in the prompt). Redundant Facts are always insufficient (since you already had the information, the Fact does not offer anything new).

Here, we're told that Rick can solve X problems per minute and Matt can solve Y problems per minute. Neither of these 2 variables can be negative (a person cannot solve "negative" problems in the context of this question). We're also told that Y CANNOT be 0. As such, X/Y is either 0 or it's positive, so the information that -(X/Y) < 3 is redundant, since -(X/Y) is either 0 or it's negative and ALL of those possibilities are LESS than +3. Thus, Fact 2 is INSUFFICIENT.

While redundant information isn't that common on the Official GMAT, you'll likely have to deal with it at least once, so it's important to take the proper notes and make whatever deductions you can with the information that appears in the prompt.

GMAT assassins aren't born, they're made,
Rich


hi empower ,
u are right that many times, there are redundant information...
But not in this case. Its very importantto read finer point between the lines..
it gives the speed as problems per minute.. now either a problem is solved or not solved, we cannot have a half solved problem..
this does mean that x and y are integers....
this is what i feel, although it may be possible the Q was not meant that way..
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 06 Feb 2015, 00:32
1
chetan2u wrote:
EMPOWERgmatRichC wrote:
Hi All,

Certain DS questions on the Official GMAT will include a "redundant" piece of information in one (or both) of the two Facts. By 'redundant', I mean that it is information that was either already given in the prompt (or something that you can deduce from the information in the prompt). Redundant Facts are always insufficient (since you already had the information, the Fact does not offer anything new).

Here, we're told that Rick can solve X problems per minute and Matt can solve Y problems per minute. Neither of these 2 variables can be negative (a person cannot solve "negative" problems in the context of this question). We're also told that Y CANNOT be 0. As such, X/Y is either 0 or it's positive, so the information that -(X/Y) < 3 is redundant, since -(X/Y) is either 0 or it's negative and ALL of those possibilities are LESS than +3. Thus, Fact 2 is INSUFFICIENT.

While redundant information isn't that common on the Official GMAT, you'll likely have to deal with it at least once, so it's important to take the proper notes and make whatever deductions you can with the information that appears in the prompt.

GMAT assassins aren't born, they're made,
Rich


hi empower ,
u are right that many times, there are redundant information...
But not in this case. Its very importantto read finer point between the lines..
it gives the speed as problems per minute.. now either a problem is solved or not solved, we cannot have a half solved problem..
this does mean that x and y are integers....
this is what i feel, although it may be possible the Q was not meant that way..


Hi chetan2u,

If you reread my post, you'll see that I made no reference to whether X and Y were integers or not (that point is irrelevant), only that X/Y had to be 0 or positive. As such -(X/Y) will EITHER be 0 or a negative value, so -(X/Y) will ALWAYS be less than 3, regardless of the values.

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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 06 Feb 2015, 01:44
EMPOWERgmatRichC wrote:
chetan2u wrote:

hi empower ,
u are right that many times, there are redundant information...
But not in this case. Its very importantto read finer point between the lines..
it gives the speed as problems per minute.. now either a problem is solved or not solved, we cannot have a half solved problem..
this does mean that x and y are integers....
this is what i feel, although it may be possible the Q was not meant that way..


Hi chetan2u,

If you reread my post, you'll see that I made no reference to whether X and Y were integers or not (that point is irrelevant), only that X/Y had to be 0 or positive. As such -(X/Y) will EITHER be 0 or a negative value, so -(X/Y) will ALWAYS be less than 3, regardless of the values.

GMAT assassins aren't born, they're made,
Rich


hi rich...
you may not have meant it, so it's perfectly fine. but my point is in general that even a sentence such as 'Rick can solve x algebra problems per minute. Matt can solve y calculus problems per minute'. can give us a point to move on... but as you say it was statement two which is renundant. this too may not be correct as the Q says x/y>3 and statement 2 when simplified tells us x/y>-3.. two different things..
i think i actually require to read Q again .. but kudos to you...
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 06 Feb 2015, 07:32
bankerboy30 wrote:
Doesn't it become x/y>-3?

Yes, you're right.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 09 Feb 2015, 05:12
Bunuel wrote:
Rick can solve x algebra problems per minute. Matt can solve y calculus problems per minute. If y is not equal to zero, is x/y > 3?

(1) x > 3
(2) –(x/y) < 3

Kudos for a correct solution.


VERITAS PREP OFFICIAL SOLUTION:

Solution: E

Statement (1) only tells us about x; INSUFFICIENT. Statement (2) can be rewritten as (-x)/y < 3. Y cannot be negative – no one does “negative” calculus problems per minute – so it must be positive. This means that we can multiply both sides by y knowing that the sign won’t flip, so –x < 3y. Multiplying both sides by -1 gives us x > -3y, and dividing by y gives us x/y > -3; INSUFFICIENT. Combined the statements are still insufficient: we could have x/y = 5/1, as that’s greater than -3, and we could have x/y = 4/3, as that’s also greater than -3. (E).
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 22 Nov 2016, 09:06
Bunuel wrote:
Rick can solve x algebra problems per minute. Matt can solve y calculus problems per minute. If y is not equal to zero, is x/y > 3?

(1) x > 3
(2) –(x/y) < 3

Kudos for a correct solution.


xexe...this one wants to trick you to pick B...
1 clearly insufficient.
2 multiply both sides by -1, and flip the inequality sign: x/y > -3 - not sufficient

1+2
x=4, y=2, nope
x=4, y=1, yes

1+2 not sufficient.

answer is E.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 22 Nov 2016, 10:29
Answer: E
S#1: x > 3
Mentioned about only x, so not sufficient

S#2:
–(x/y) < 3
x/y > -3 [flipped the inequality sign as multiplied by '-']

'> -3' only gives the starting range of the possible values that x/y can have, so we can come up with different values of x/y
case 1: x/y = 5, which satisfies x/y > -3, giving us YES for x/y >3
case 2: x/y = 2, which satisfies x/y > -3, giving us NO for x/y > 3
Therefore, not sufficient

S#1 + S#2:
x > 3 and x/y > -3
These give only the starting range of the possible values x/y can have, so we can come up with different values of x/y

case 1: x/y = 15/3 = 5, which satisfies x>3 and x/y > -3, giving us YES for x/y >3
case 2: x/y = 4/2 = 2, which satisfies x>3 and x/y > -3, giving us NO for x/y > 3

Therefore, not sufficient. Answer E.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 18 Dec 2016, 19:30
IMO: E

Statement 1 : clearly insufficient.
Statement 2 : Since we know that x and y are rates. They can not be negative.
(x/y)>0
Hence -(x/y)<0.
So -(x/y)<3 is not useful.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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New post 22 Dec 2016, 08:36
sterling19 wrote:
Statement 1: x > 3 does not give any information on y and x could be an infinite number of values
Statement 2: dividing by a negative value in an inequality reverses the sign so if we divide both sides of the inequality by -1 then -(x/y) < 3 becomes (x/y) > 3 which is sufficient to answer the question.

The correct answer is B.


well...i guess we both made the same silly mistake-forgot to change the sign of "3"...arghhh.
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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu  [#permalink]

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Re: Rick can solve x algebra problems per minute. Matt can solve y calculu   [#permalink] 25 Aug 2019, 12:12
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