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 Author: Bunuel [ 18 May 2017, 00:29 ] Post subject: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? (1) ab=c (2) ab=ac+bc

 Author: obliraj [ 18 May 2017, 00:55 ] Post subject: Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? Answer A.3/a + 3/b = 3/c1/a + 1/b = 1/c(a+b)/ab = 1/ca+b = ab/cSt 1: ab = c ; i.e a+b=1----- sufficientSt 2: ab=ac+bc; ab=c(a+b); a+b=ab/c---- cannot find a+b----- Insufficient.

 Author: Nunuboy1994 [ 20 May 2017, 07:37 ] Post subject: Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? obliraj wrote:Answer A.3/a + 3/b = 3/c1/a + 1/b = 1/c(a+b)/ab = 1/ca+b = ab/cSt 1: ab = c ; i.e a+b=1----- sufficientSt 2: ab=ac+bc; ab=c(a+b); a+b=ab/c---- cannot find a+b----- Insufficient.It's because if the we know the product of a and b equals the numerator of 1/c or c then the top we can just set equal to a + b= 1 HenceA

 Author: abhishekdadarwal2009 [ 05 Feb 2019, 11:49 ] Post subject: Re: abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? abc≠0 and 3/a + 3/b = 3/c. What is the sum a+b? (1) ab=c (2) ab=ac+bc solution:3/a+3/b=3/c =3(a+b)/ab=3/c.1.ab=c ,substitute in the above equation we get a+b=1.A is sufficient2.ab=c(a+b), substitute in equation above, we get 1/c so it provies the same info that we already know. so not sufficientA is the correct answer.

 Author: bumpbot [ 24 Dec 2022, 04:47 ] Post subject: Re: abc0 and 3/a + 3/b = 3/c. What is the sum a+b? Hello from the GMAT Club BumpBot!Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

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