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Smallest Common Multiple

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by akhpad » Sun Apr 25, 2010 7:45 am
250 = 5*5*5*2

Smallest common multiple = 250*2, 250*3, 250*4 so on

Answer: 4
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by Stuart@KaplanGMAT » Sun Apr 25, 2010 1:56 pm
deepesh.gupta wrote:What is the smallest common multiple of two integers which are both greater than 250?
1) 251
2) 252
3) 502
4) 750
5) 884
Hi,

we have to be very careful about not making assumptions on the GMAT; the GMAT uses very precise language and we should never "read in" a word that isn't actually there.

One commonly tested case involves the word "distinct", which simply means "different" - you have to be very careful not to add that word to a question.

This question is a perfect example - nowhere does it say that the two integers have to be distinct integers.

Accordingly, we can pick 251 and 251 as our two integers, which have a lowest common multiple of 251: choose (1).
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by Stuart@KaplanGMAT » Sun Apr 25, 2010 1:57 pm
akhp77 wrote:250 = 5*5*5*2

Smallest common multiple = 250*2, 250*3, 250*4 so on

Answer: 4
The question doesn't ask which number is the smallest common multiple of 250 - it asks for the SCM of two integers, both greater than 250.
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by niksdoon » Mon Apr 26, 2010 10:52 am
Hi Stuart,

What if question would've included "distinct" in the question. What would have been our answer in that case?

I couldn't understand solution provided by akhp77.

Please advise !!

Thanks,
Niks
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by Stuart@KaplanGMAT » Mon Apr 26, 2010 3:04 pm
niksdoon wrote:Hi Stuart,

What if question would've included "distinct" in the question. What would have been our answer in that case?

I couldn't understand solution provided by akhp77.

Please advise !!

Thanks,
Niks
With "distinct" the answer would have been 502; to generate the smallest common multiple of two distinct numbers, both greater than 250, we take the smallest number we can (251) and then double it (502) - the SCM of 251 and 502 is 502.
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by akhpad » Mon Apr 26, 2010 6:20 pm
I have understood what mistake I did.

What is the smallest common multiple of two integers which are both greater than 250?

1st integer 251, 2nd integer 251
smallest common multiple = 251


What is the smallest common multiple of two distinct integers which are both greater than 250?

1st integer 251, 2nd integer 502
smallest common multiple = 502

Thanks Staurt
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by deepesh.gupta » Wed Apr 28, 2010 6:25 pm
Thanks Stuart.

I made the mistake of 'distinct' and arrived at 502. But not that we need to be really careful with such details.

OA is 1
Stuart Kovinsky wrote:
akhp77 wrote:250 = 5*5*5*2

Smallest common multiple = 250*2, 250*3, 250*4 so on

Answer: 4
The question doesn't ask which number is the smallest common multiple of 250 - it asks for the SCM of two integers, both greater than 250.
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by barracuda939 » Sat Jan 08, 2011 6:10 am
Can you help me over here Stuart?

The question states that what is the smallest common multiple of two numbers greater than 250.

In this case,
the two numbers = 251 and 251.

Multples of 251 : 251,502.....
Thus smallest = 251.

But if the question were to ask DISTINCT numbers, how could the answer be 502?
251: 251,502
252: 252, 504...
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by ankur.agrawal » Sat Jan 08, 2011 7:19 am
barracuda939 wrote:Can you help me over here Stuart?

The question states that what is the smallest common multiple of two numbers greater than 250.

In this case,
the two numbers = 251 and 251.

Multples of 251 : 251,502.....
Thus smallest = 251.

But if the question were to ask DISTINCT numbers, how could the answer be 502?
251: 251,502
252: 252, 504...
I think u r still getting the language wrong.

Question is asking LCM of two numbers greater than 250.

So lets start with 251. now we have to select another integer. How do we do that?

Lets try : try 252,253, 300. Lets take LCM of 251 & 300. Cant. Lets go further. 251 & 400. still doesnt work. Now we can think of 502. LCM of 251 & 502. Dat will be 502 ( hope u r clear on this).

I think looking at the options gives us a direction to solve this problem.

Hope its clear now.
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by sangya » Mon Feb 21, 2011 5:38 am
Stuart Kovinsky wrote:
deepesh.gupta wrote:What is the smallest common multiple of two integers which are both greater than 250?
1) 251
2) 252
3) 502
4) 750
5) 884
Hi,

we have to be very careful about not making assumptions on the GMAT; the GMAT uses very precise language and we should never "read in" a word that isn't actually there.

One commonly tested case involves the word "distinct", which simply means "different" - you have to be very careful not to add that word to a question.

This question is a perfect example - nowhere does it say that the two integers have to be distinct integers.

Accordingly, we can pick 251 and 251 as our two integers, which have a lowest common multiple of 251: choose (1).

Thanks Stuart...... never realized... came across this question few times but always chose 502
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by cuty » Mon Mar 21, 2011 9:43 pm
Thanks stuart ........actually last week i came across the same question in my Kap test and i didn't satisfied with explanation n totally confused.

Now cleared my doubt :)
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by Yolanda Gallipoli » Thu Aug 11, 2011 9:13 am
The smallest Common Multiple between 502 and 251 is 502 "C"
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by saketk » Mon Sep 05, 2011 10:14 pm
Yolanda Gallipoli wrote:The smallest Common Multiple between 502 and 251 is 502 "C"
Hi - read the post by Stuart. The answer is option A
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by zander21 » Fri Sep 09, 2011 2:52 pm
Stuart Kovinsky wrote:
deepesh.gupta wrote:What is the smallest common multiple of two integers which are both greater than 250?
1) 251
2) 252
3) 502
4) 750
5) 884
Hi,

we have to be very careful about not making assumptions on the GMAT; the GMAT uses very precise language and we should never "read in" a word that isn't actually there.

One commonly tested case involves the word "distinct", which simply means "different" - you have to be very careful not to add that word to a question.

This question is a perfect example - nowhere does it say that the two integers have to be distinct integers.

Accordingly, we can pick 251 and 251 as our two integers, which have a lowest common multiple of 251: choose (1).
That's the first thing i thought of, but I made the mistake of thinking GMAT wanted them to be two distinct integers, so I went for 502 (251 & 502). Thanks for the reminder not to "assume." i guess I assumed GMAT was being tricky (which they are!) but it hurt me there.
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