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DILIP
 
 

D.S - GMAT PREP

by DILIP Mon Sep 08, 2008 12:12 pm

If a,b,c are integers , wht is the value of a?

1. (a-7)(b-7)(c-7)=0
2. bc= 18

answer is C,

Can anyone help me to solve this Data sufficiency problem
Raj
 
 

Re: D.S - GMAT PREP

by Raj Mon Sep 08, 2008 1:50 pm

From (1), at least one of a,b,c = 7

From (2), b &c are not 7

From (1) and (2), a = 7.

-Raj.

DILIP Wrote:If a,b,c are integers , wht is the value of a?

1. (a-7)(b-7)(c-7)=0
2. bc= 18

answer is C,

Can anyone help me to solve this Data sufficiency problem
DILIP
 
 

by DILIP Tue Sep 09, 2008 7:47 am

Thanks Raj, it was so easy, i don;t know where i got confused
RonPurewal
Students
 
Posts: 19744
Joined: Tue Aug 14, 2007 8:23 am
 

Re: D.S - GMAT PREP

by RonPurewal Mon Sep 29, 2008 6:21 am

Raj Wrote:From (1), at least one of a,b,c = 7

From (2), b &c are not 7

From (1) and (2), a = 7.

-Raj.

DILIP Wrote:If a,b,c are integers , wht is the value of a?

1. (a-7)(b-7)(c-7)=0
2. bc= 18

answer is C,

Can anyone help me to solve this Data sufficiency problem


well played.

--

moral of the story:
DO NOT IGNORE CONDITIONS.

if they go out of their way to tell you that numbers are INTEGERS - or if they imply that the numbers must be integers, usually by making them part of a word problem (e.g., you can't have, say, fractional numbers of people) - then this fact will almost certainly play a pivotal role in the solution of the problem.
the exception, if you want to call it that, is divisibility problems; they'll always restrict divisibility problems to integers, so that they don't have to deal with weird questions such as whether decimals like 0.5 are factors of a given number.