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D01-12

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Re: D01-12  [#permalink]

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New post 05 May 2016, 07:51
amilbusthon wrote:
I think this is a poor-quality question and I don't agree with the explanation. (2) @@ is divisible by 9. can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient. So it could be 12340 or 12349 but these are not divisible by 9. It should be 12348, because the sum of 1+2+3+4+8 is divisible by 9.


The statement talks of @, the units digit, to be div by 9 so it has to be 0 or 9..
why are you confusing it with 1234@ being div by 9..
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New post 27 Jul 2016, 13:09
I think this is a high-quality question and I agree with explanation.
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New post 08 Aug 2016, 19:18
Hello, regardin the first condition, why @ can't be 6 or 7? both ! are not divisible by 5.

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New post 10 Feb 2017, 20:19
This s an excellent question, tests logic very well and if done right, saves quite a bit time.
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New post 06 Mar 2017, 20:16
(1) @! is not divisible by 5. Can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2) @ is divisible by 9. Can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.



Can someone please explain (1) to me? How is it that 0! works if it meets the criteria that it is NOT divisible by 5? You can divide 0/5. So that means @ would have to equal 1, 2 3, or 4. Which means that combining 1& 2 wouldn't work and answer would be E.

Getting lost on this point...thank you!
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New post 07 Mar 2017, 01:33
bananasss wrote:
(1) @! is not divisible by 5. Can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2) @ is divisible by 9. Can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.



Can someone please explain (1) to me? How is it that 0! works if it meets the criteria that it is NOT divisible by 5? You can divide 0/5. So that means @ would have to equal 1, 2 3, or 4. Which means that combining 1& 2 wouldn't work and answer would be E.

Getting lost on this point...thank you!


(1) says that @! (factorial of number @) is NOT divisible by 5. can be 0 because @! = 0! = 1 and 1 is NOT divisible by 5.
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New post 07 Mar 2017, 07:59
Bunuel wrote:
bananasss wrote:
(1) @! is not divisible by 5. Can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2) @ is divisible by 9. Can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for @ from (1) and (2) is @=0. Sufficient.



Can someone please explain (1) to me? How is it that 0! works if it meets the criteria that it is NOT divisible by 5? You can divide 0/5. So that means @ would have to equal 1, 2 3, or 4. Which means that combining 1& 2 wouldn't work and answer would be E.

Getting lost on this point...thank you!


(1) says that @! (factorial of number @) is NOT divisible by 5. be 0 because @! = 0! = 1 and 1 is NOT divisible by 5.


OK brilliant thank you...Had no idea 0!=1, which changes everything, of course.
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New post 15 Jun 2017, 05:54
@ is divisible by 9

You have to be very careful in GMAT. It is such a small thing to overlook.
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New post 01 Jul 2017, 07:01
Bunnel
The question stem tells us that @ is either (0 or 5) as N is divisible by 5 .
I Think we can get a unique answer with statement A because 1 is not divisible by 5 whereas 5! is divisible by 5 .
I cannot understand why you have checked for @ {1,2,3,4} as we have already narrowed our search down to @{0,5}.
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New post 01 Jul 2017, 08:21
akshaypareek312 wrote:
Bunnel
The question stem tells us that @ is either (0 or 5) as N is divisible by 5 .
I Think we can get a unique answer with statement A because 1 is not divisible by 5 whereas 5! is divisible by 5 .
I cannot understand why you have checked for @ {1,2,3,4} as we have already narrowed our search down to @{0,5}.


You should read question and solution more carefully. The question does NOT say that @ equals to 0 or 5. The question asks whether @ equals to 0 or 5. From (1) if @ is 0, then the answer to the question is YES but if @ is 1, 2, 3, or 4, then the answer to the question is NO.
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New post 02 Oct 2017, 20:01
I think this is a poor-quality question and I don't agree with the explanation. wrong answer
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New post 02 Oct 2017, 20:04
amar.igtr wrote:
I think this is a poor-quality question and I don't agree with the explanation. wrong answer


The question is 100% correct. I suggest to read carefully the solution and the whole thread once more. If you still have questions you are welcome to post.
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New post 17 Oct 2017, 19:19
I think this is a high-quality question and I agree with explanation.
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New post 19 Nov 2017, 05:46
I think this is a high-quality question and I agree with explanation.
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New post 25 Nov 2017, 01:48
I think this is a high-quality question and I agree with explanation.
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New post 19 May 2018, 11:46
Bunuel wrote:
If \(N = 1234@\) and \(@\) represents the units digit of \(N\), is \(N\) a multiple of 5?


(1) \(@!\) is not divisible by 5

(2) \(@\) is divisible by 9


This is a great question.
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New post 19 Sep 2018, 00:38
@! is not divisible by 5. can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.
Here N's Unit Digit is https://gmatclub.com:443/forum/memberlist.php?mode=viewprofile&un=, not @! so why you consider 0 here ... can be 1,2,3,4 only..
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D01-12  [#permalink]

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New post 19 Sep 2018, 01:47
ARVINDSHARMA wrote:
@! is not divisible by 5. can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.
Here N's Unit Digit is https://gmatclub.com:443/forum/memberlist.php?mode=viewprofile&un=, not @! so why you consider 0 here ... can be 1,2,3,4 only..


0! = 1, which is NOT divisible by 5. So, \(@\) be 0.
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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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Re: D01-12  [#permalink]

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New post 26 Nov 2018, 11:38
integer 0 is going to ruin my life.
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Re: D01-12 &nbs [#permalink] 26 Nov 2018, 11:38

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