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but stmnt 2 is not suff since a and b might be equal and in this case there will be two possible common divisors and the integer itself will be the greates coomon divisor.
Ex: a=5, b = 3 GCD = 1
a=7 b=7 GCD is 7

Oh my God.
Very good trap. I believe no matter how much I practice, someday somewhere I can fell into trap.....
Thanks CAAS for posting such a nice question. Btw what is the source of the question.

Oh my God. Very good trap. I believe no matter how much I practice, someday somewhere I can fell into trap..... Thanks CAAS for posting such a nice question. Btw what is the source of the question.

yeah I made the same mistake
sorry, don't remember the source
it was in my notes "my wrong DS"

Your saying for statement 2, if the values are 7 and 7 (two identical primes) it has more then one greatest common divisor? I don't follow. Wouldn't the greatest common divisor just be 7?

Your saying for statement 2, if the values are 7 and 7 (two identical primes) it has more then one greatest common divisor? I don't follow. Wouldn't the greatest common divisor just be 7?

scenario A: two different numbers: 2 and 3 yields a GCF of 1 scenario B: same numbers: 2 and 2: GCF 2

we cant determine a hard # for the value of GCF
_________________

You tried your best and you failed miserably. The lesson is 'never try'. -Homer Simpson

Your saying for statement 2, if the values are 7 and 7 (two identical primes) it has more then one greatest common divisor? I don't follow. Wouldn't the greatest common divisor just be 7?

scenario A: two different numbers: 2 and 3 yields a GCF of 1 scenario B: same numbers: 2 and 2: GCF 2

we cant determine a hard # for the value of GCF

oooooooooooh. got it. thanks...

gmatclubot

Re: DS - GCD of a and b
[#permalink]
06 Mar 2008, 17:53