Divisibility and Prime Factoring

yes divisible by 12 and 10 thus 12 and 2*5 or 24 and 5

mchaubey wrote:yes divisible by 12 and 10 thus 12 and 2*5 or 24 and 5

No it's not.

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

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

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]

Which variety of GMAT question is this? PS or DS? It's neither I guess. But liferocks' explanation is perfect!

sanju09 wrote:

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]

Which variety of GMAT question is this? PS or DS? It's neither I guess. But liferocks' explanation is perfect!

You are right.. it's neither.. just a plain question