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If a and b are integers, and a not= b, is |a|b > 0? (1)

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If a and b are integers, and a not= b, is |a|b > 0? (1) [#permalink] New post 20 Dec 2006, 14:21
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If a and b are integers, and a not= b, is |a|b > 0?

(1) |a^b| > 0

(2) |a|^b is a non-zero integer
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 [#permalink] New post 20 Dec 2006, 14:37
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(E) for me.

|a|*b > 0 ?
<=> b > 0 ?

From (1)
|a^b| > 0

o If b=-1 and a=1, 1 > 0 and b < 0
o If b=1 and a=-1, 1 > 0 and b > 0

INSUFF.

From (2)
|a|^b is a non zero integer implies that b must be positive or equal to 0 in order to not create a real number such as 2^-1.

So, we remains with the cases of b = 0 and b > 0.

INSUFF.

Both (1) and (2)
It brings nothing more.

INSUFF.
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 [#permalink] New post 20 Dec 2006, 17:10
my answer is E

Given: a , b are ints. and a is different from b
asking: |a| * b > 0


what the question is really asking if b > 0 [ |a| is always >0 ]

(1) |a^b| >0
----------------
says nothing, cuz |x| is always > 0
statement 1 is insufficient

(2) |a|^b is not zero
-------------------------
also says nothing .. we know |a|^b > 0
b could be -ve or +ve
statement 2 is insufficient

(1) and (2) together
------------------------
both statements really say nothing about b

final answer is E
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 [#permalink] New post 16 Jan 2007, 20:49
is |a|b > 0 is same as, is b > 0

stat 1 is not sufficient since all it says is that a <> 0

from stat 2 b>= 0 since a only negative value of b can cause |a|^b to be not a non zero integer

so E ?
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Re: DS_If a and b.... [#permalink] New post 16 Jan 2007, 21:39
mm007 wrote:
If a and b are integers, and a not= b, is |a|b > 0?
(1) |a^b| > 0
(2) |a|^b is a non-zero integer


First of all, the question is equivalent to: is a<>0 AND b>0?

(1) For |a^b| > 0, a could be <>0 but b could be <0 OR b>0 => insuff => B, C, or E.

(2) This is a similar case to (1): b, similarly to a, could be <>0 => insuff => C or E.

(1&2) Again, similar case to (1) and (2): b could be +ve or -ve => insuff => E.
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 [#permalink] New post 16 Jan 2007, 23:03
Quote:
If a and b are integers, and a not= b, is |a|b > 0?
(1) |a^b| > 0
(2) |a|^b is a non-zero integer

E2

I rephrased the stem to "is |a|>0 and is b -ve, 0 or +ve?"

1) |a^b| will always be +ve. But here, b can be greater than or equal to 0 and |a^b| will still be +ve
INS

2) |a|^b. Here, |a| cannot be 0 but B can be 0 or 1. b can't be -ve b/c |a|^b will become a non-integer, 1/a^b.
INS

Taken together, we're still not told anything about b. If we can't figure what b is we can't do much with this prob.
INS
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Re: [#permalink] New post 10 Sep 2009, 03:55
Can anybody chime in? Although I agree with the answer, I don't think the bold statement below is correct. B does not have to be
0 or greater. It can be -4 if A is 1.

If b= -4 and a=1. this satisfiies the conditions: 1) a,b are integers 2) a is not equal to b 3) statement 2; 1^(-4)=1. that is a non-zero integer. So you can't say B is definitely positive or 0. Combining statement 1 and 2. You can't determine if A is a 1 or not so E.

Please correct me if I am wrong. Thanks.

Fig wrote:
(E) for me.

|a|*b > 0 ?
<=> b > 0 ?

From (1)
|a^b| > 0

o If b=-1 and a=1, 1 > 0 and b < 0
o If b=1 and a=-1, 1 > 0 and b > 0

INSUFF.

[b]From (2)
|a|^b is a non zero integer implies that b must be positive or equal to 0 in order to not create a real number such as 2^-1.

So, we remains with the cases of b = 0 and b > 0.[/b]
INSUFF.

Both (1) and (2)
It brings nothing more.

INSUFF.
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Re: DS_If a and b.... [#permalink] New post 26 Nov 2009, 19:34
mm007 wrote:
If a and b are integers, and a not= b, is |a|b > 0?

(1) |a^b| > 0

(2) |a|^b is a non-zero integer


Clearly E.
|a^b| and |a|^b are always >0, no matter what b is, because absolute value is always greater than 0.
Thus, we can't know if b>0 or not.
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Re: DS_If a and b.... [#permalink] New post 21 Dec 2009, 08:22
mm007 wrote:
If a and b are integers, and a not= b, is |a|b > 0?

(1) |a^b| > 0

(2) |a|^b is a non-zero integer




Question is |a|b>0 this can be proved if we can prove that a not=0 and b>0.
1. |a^b| > 0 implies that a not = 0. a can be +ve or -ve, and be can be 0, +ve or -ve....but we are sure that a not=0 else |a^b| = 0.
Statement 1 itself is insuff.

2. |a|^b is a non zero integer.
we already know a,b both are integers....|a| is > 0, so b >= 0.
No clear value of b...

So ans E.
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Re: [#permalink] New post 15 Sep 2010, 08:15
Mishari wrote:
my answer is E

Given: a , b are ints. and a is different from b
asking: |a| * b > 0


what the question is really asking if b > 0 [ |a| is always >0 ]

(1) |a^b| >0
----------------
says nothing, cuz |x| is always > 0
statement 1 is insufficient

(2) |a|^b is not zero
-------------------------
also says nothing .. we know |a|^b > 0
b could be -ve or +ve
statement 2 is insufficient

(1) and (2) together
------------------------
both statements really say nothing about b

final answer is E



>>Please tell me how can |a| be taken as positive in the above steps without knowing its sign..I mean if a is negative,then |a| wil be negative..Right?Am i missing anythin badly?
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Re: Re: [#permalink] New post 15 Sep 2010, 08:39
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ravitejapandiri wrote:
>>Please tell me how can |a| be taken as positive in the above steps without knowing its sign..I mean if a is negative,then |a| wil be negative..Right?Am i missing anythin badly?


Absolute value of of an expression is alway non-negative: |some \ expression|\geq{0}. Please check Walker's post on Absolute Value at: math-absolute-value-modulus-86462.html

As for the question:

If a and b are integers, and a does not equal to b, is |a|*b > 0?
(1) |a^b| > 0
(2) |a|^b is a non-zero integer.

|a|*b>0 is true when b>0 and a does not equal to zero.

(1) |a^b| > 0 --> a does not equal to zero, but we don't know about b, it can be any value, positive or negative. Not sufficient.

(2) |a|^b is a non-zero integer --> a can be 1 and b any integer, positive or negative. Not sufficient.

(1)+(2) If a=1 and b=2, then |a|*b>0, but if a=1 and b=-2, then |a|*b<0. Not sufficient.

Answer: E.

Other discussion of this question at: good-set-of-ds-85413.html
Similar question: the-power-of-absolutes-manhattan-challenge-problem-101661.html

Hope it helps.
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Re: DS question : need help [#permalink] New post 28 Oct 2010, 18:20
Basically just need to find out if b is positive or negative, since a will always be positive as it is inside of the | |.

1) Doesn't give you anything because everything is inside of the | |, so you can't tell if b is positive or negative, so insufficient.

2) Tells you that b is not negative since that would result in a non-integer. However, b could be 0 since a number raised to the 0 is 1, which is a non-integer number. Also insufficient.

Using both statements still doesn't provide anything because b can still be equal to 0, in which case |a|b > 0 is false. However, b can also be any positive number which would make |a|b > 0 true. Thus E.
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Re: If a and b are integers, and a not= b, is |a|b > 0? (1) [#permalink] New post 04 Jun 2014, 18:35
The reason why s2 alone or taken together with s1 is not sufficient bcos we need info on the signs that is, a is +ve or -ve and whether b is +ve or -ve & not wether they are zero or non-zero integers.
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Re: If a and b are integers, and a not= b, is |a|b > 0? (1) [#permalink] New post 02 Sep 2014, 03:43
Bunuel wrote:
ravitejapandiri wrote:
>>Please tell me how can |a| be taken as positive in the above steps without knowing its sign..I mean if a is negative,then |a| wil be negative..Right?Am i missing anythin badly?


Absolute value of of an expression is alway non-negative: |some \ expression|\geq{0}. Please check Walker's post on Absolute Value at: math-absolute-value-modulus-86462.html

As for the question:

If a and b are integers, and a does not equal to b, is |a|*b > 0?
(1) |a^b| > 0
(2) |a|^b is a non-zero integer.

|a|*b>0 is true when b>0 and a does not equal to zero.

(1) |a^b| > 0 --> a does not equal to zero, but we don't know about b, it can be any value, positive or negative. Not sufficient.

(2) |a|^b is a non-zero integer --> a can be 1 and b any integer, positive or negative. Not sufficient.

(1)+(2) If a=1 and b=2, then |a|*b>0, but if a=1 and b=-2, then |a|*b<0. Not sufficient.

Answer: E.

Other discussion of this question at: good-set-of-ds-85413.html
Similar question: the-power-of-absolutes-manhattan-challenge-problem-101661.html

Hope it helps.


Hi Bunuel,
I've always struggled when to consider 0 as an integer and when not. Is there any concept that you can share? Appreciate your help!!
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If a and b are integers, and a not= b, is |a|b > 0? (1) [#permalink] New post 02 Sep 2014, 03:49
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shahPranay14 wrote:
Bunuel wrote:
ravitejapandiri wrote:
>>Please tell me how can |a| be taken as positive in the above steps without knowing its sign..I mean if a is negative,then |a| wil be negative..Right?Am i missing anythin badly?


Absolute value of of an expression is alway non-negative: |some \ expression|\geq{0}. Please check Walker's post on Absolute Value at: math-absolute-value-modulus-86462.html

As for the question:

If a and b are integers, and a does not equal to b, is |a|*b > 0?
(1) |a^b| > 0
(2) |a|^b is a non-zero integer.

|a|*b>0 is true when b>0 and a does not equal to zero.

(1) |a^b| > 0 --> a does not equal to zero, but we don't know about b, it can be any value, positive or negative. Not sufficient.

(2) |a|^b is a non-zero integer --> a can be 1 and b any integer, positive or negative. Not sufficient.

(1)+(2) If a=1 and b=2, then |a|*b>0, but if a=1 and b=-2, then |a|*b<0. Not sufficient.

Answer: E.

Other discussion of this question at: good-set-of-ds-85413.html
Similar question: the-power-of-absolutes-manhattan-challenge-problem-101661.html

Hope it helps.


Hi Bunuel,
I've always struggled when to consider 0 as an integer and when not. Is there any concept that you can share? Appreciate your help!!


0 is neither positive nor negative even integer.

Check for more here: number-properties-tips-and-hints-174996.html
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


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If a and b are integers, and a not= b, is |a|b > 0? (1)   [#permalink] 02 Sep 2014, 03:49
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