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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
This is a great post.
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
EgmatQuantExpert wrote:
Product of all integers in the set = GCD * LCM

Hi Harsh
is this statement applicable only in a case of only two integers? so GCD(M, N) × LCM(M, N) = M × N,

how that's working for example for the following set {2,4,8}
their product = 64
whilst GCD * LCM = 2 * 16 = 32
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Thank you for this post.

To find the GCD, I want to know if the below process always gives the correct answer.

1) write in the form of Prime Factors.
Say 12,18
12 - 2^2 x 3^1
18 - 2^1 x 3^2

2) Taking the factors common between them
Common - 2^1 x 3^1 = 6
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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cbh wrote:
EgmatQuantExpert wrote:
Product of all integers in the set = GCD * LCM

Hi Harsh
is this statement applicable only in a case of only two integers? so GCD(M, N) × LCM(M, N) = M × N,

how that's working for example for the following set {2,4,8}
their product = 64
whilst GCD * LCM = 2 * 16 = 32


Hey cbh,

Yes the formula GCD(M,N) * LCM(M,N) = M x N, is applicable only for two variables.

We can create similar formulas for 3 or more variables, but that would be really out of scope for GMAT exam and I would not bother learning another new formula, which might not be used at all. :)


Regards,
Saquib
e-GMAT Quant Expert


Originally posted by EgmatQuantExpert on 29 Dec 2017, 23:27.
Last edited by EgmatQuantExpert on 07 Aug 2018, 00:57, edited 1 time in total.
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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siddharthselvamohan wrote:
Thank you for this post.

To find the GCD, I want to know if the below process always gives the correct answer.

1) write in the form of Prime Factors.
Say 12,18
12 - 2^2 x 3^1
18 - 2^1 x 3^2

2) Taking the factors common between them
Common - 2^1 x 3^1 = 6



Hey Siddharth,


Yes, the method that you have used will always give you the correct answer. :)


Regards,
Saquib
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Hey everyone,

We have added a few practice question on the application of LCM and GCD

Practice Question #1
Practice Question #2
Practice Question #3

Regards,
Tamal
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Hey everyone,

The official answers to all the practice questions have been posted.

Regards,
Tamal
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Dear Students,



We have added a new article to help you to avoid common mistakes made, while solving questions on Remainders.

You can go through the article from this Common Mistakes One Must Avoid in Remainders

Stay tuned for more articles.

Happy learning :)

Regards,
Sandeep
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
Thank you! Found this very helpful
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
Such a helpful post. A much needed one, infact. Thanks!
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3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Dear Students,

We have added a new article to discuss two interesting applications of Remainders.

You can go through the article from this Interesting Applications of Remainders

Stay tuned for more articles.

Happy learning :)

Regards,
Tamal
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Dear Students,

We have added a new article to discuss the variations in factorial manipulation.

You can go through the article from this Variations in Factorial Manipulation

Stay tuned for more articles.

Happy learning :)

Regards,
Sandeep.
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
Kindly add the pdf.
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Hey Everyone,

We have posted the official solutions to all the practice questions.

Regards,
Sandeep
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
Please add PDF. e-GMAT team.
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3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Hey Everyone,



We've added 4 new practice questions in which you can apply your learnings of Number Properties.

Exercise Questions


Question 1

Question 2

Question 3

Question 4

Detailed solutions will be posted soon.


Happy Learning! :)
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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Hey Everyone,

We have posted the official solutions to all the practice questions.

Regards,
Sandeep
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Re: 3 Deadly Mistakes you must avoid in LCM-GCD Questions [#permalink]
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