Source: MGMAT
If j is divisible by 12 and 10, is j divisible by 24?
Ans: [spoiler]CANNOT BE DETERMINED
Please explain. The explanation make sense but I could not generalize it and I have seen this specific problem types before and I always get it wrong.[/spoiler]
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Divisibility and Prime Factoring
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jerryragland
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jerryragland
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debmalya_dutta
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it is not necessarily divisible by 24
example being 60 which is divisible by 12 and by 10
j is always a multiple of 60 though because LCM of 12 & 10 is 60
example being 60 which is divisible by 12 and by 10
j is always a multiple of 60 though because LCM of 12 & 10 is 60
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liferocks
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Here the thing to notice is the number which is divisible by both a and b has to be divisible by its LCM
in this case 12 and 10 has LCM of 60..so all the numbers divisible by 12 and 10 is a multiple of 60 ie 60,120,180...clearly all of these are not divisible by 24(60,180)..but some are(120)..so we cannot tell for sure whether the number under discussion is a multiple of 24
in this case 12 and 10 has LCM of 60..so all the numbers divisible by 12 and 10 is a multiple of 60 ie 60,120,180...clearly all of these are not divisible by 24(60,180)..but some are(120)..so we cannot tell for sure whether the number under discussion is a multiple of 24
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sanju09
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Which variety of GMAT question is this? PS or DS? It's neither I guess. But liferocks' explanation is perfect!jerryragland wrote:Source: MGMAT
If j is divisible by 12 and 10, is j divisible by 24?
Ans: [spoiler]CANNOT BE DETERMINED
Please explain. The explanation make sense but I could not generalize it and I have seen this specific problem types before and I always get it wrong.[/spoiler]
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
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www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
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jerryragland
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You are right.. it's neither.. just a plain questionsanju09 wrote:Which variety of GMAT question is this? PS or DS? It's neither I guess. But liferocks' explanation is perfect!jerryragland wrote:Source: MGMAT
If j is divisible by 12 and 10, is j divisible by 24?
Ans: [spoiler]CANNOT BE DETERMINED
Please explain. The explanation make sense but I could not generalize it and I have seen this specific problem types before and I always get it wrong.[/spoiler]
