Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.
See classesLearn live with an expert or move at your own pace. Every option includes the complete TTP study system.
Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.
with Josh Braslow, 20+ years in test prep
Self-paced EA prep. Study on your schedule.
with
Complete access from day one. Study on your schedule.
Hmm, I think this answer is . . . sometimes yes and sometimes no.Aishwarya1204 wrote:Just wanted to confirm, if we know the GCF and LCM of two numbers, we can only find out the product of 2 numbers and not the actual values of the 2 numbers right?
The only rule I came across regarding this is:
GCF of 2 numbers * LCM of two numbers = the product of the 2 numbers !
Thank you so much !Brent@GMATPrepNow wrote:Hmm, I think this answer is . . . sometimes yes and sometimes no.Aishwarya1204 wrote:Just wanted to confirm, if we know the GCF and LCM of two numbers, we can only find out the product of 2 numbers and not the actual values of the 2 numbers right?
The only rule I came across regarding this is:
GCF of 2 numbers * LCM of two numbers = the product of the 2 numbers !
For example, if the GCF of x and y is 2, and the LCM of x and y is 12, then we can conclude that xy = (2)(12) = 24. In this case, the numbers could be 4 and 6, or the numbers could be 2 and 12
Conversely, if the GCF of x and y is 3, and the LCM of x and y is 24, then we can conclude that xy = (3)(24) = 72. In this case, the numbers must be 3 and 24
So, the million dollar question is, "Under what circumstances does our rule indicate only one pair of numbers?"
I'm not too sure about that. However, I am quite certain that I've never seen an official GMAT test this rule. Although I have seen some advanced questions test the rule that says, "If the GCF of x and y is m, and if the LCM of x and y is n, then xy = mn"
Cheers,
Brent
.Brent,Brent@GMATPrepNow wrote:Hmm, I think this answer is . . . sometimes yes and sometimes no.Aishwarya1204 wrote:Just wanted to confirm, if we know the GCF and LCM of two numbers, we can only find out the product of 2 numbers and not the actual values of the 2 numbers right?
The only rule I came across regarding this is:
GCF of 2 numbers * LCM of two numbers = the product of the 2 numbers !
For example, if the GCF of x and y is 2, and the LCM of x and y is 12, then we can conclude that xy = (2)(12) = 24. In this case, the numbers could be 4 and 6, or the numbers could be 2 and 12
Conversely, if the GCF of x and y is 3, and the LCM of x and y is 24, then we can conclude that xy = (3)(24) = 72. In this case, the numbers must be 3 and 24
So, the million dollar question is, "Under what circumstances does our rule indicate only one pair of numbers?"
I'm not too sure about that. However, I am quite certain that I've never seen an official GMAT test this rule. Although I have seen some advanced questions test the rule that says, "If the GCF of x and y is m, and if the LCM of x and y is n, then xy = mn"
Cheers,
Brent
