inequality-- data sufficiency

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inequality-- data sufficiency

by adeel » Thu Aug 20, 2009 2:09 pm
Q, Is X -ve number??

1, 9x > 10x

2, x+3 is +ve

the answer is A according to gmat off guide

my Q is its easy if we take into account only integers to arrive to the ans A.

but how do u decide not to check for fractions

i.e if x =1/90

then 1 becomes 1/9 > 1/10

which is true

does the word number in the question suggest to check only for intergers,

if we need to check for fractions will the Q be only

is X +ve ??

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by adeel » Thu Aug 20, 2009 2:11 pm
sorry posted in the wrong forum should have gone to data sufficency

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by arbiter » Sat Aug 22, 2009 12:04 pm
here for x+3 to e positive , x can be either <=-3 or greater the 0. this do not give any definite x value.
hence A is the answer
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Re: inequality-- data sufficiency

by maihuna » Sat Aug 22, 2009 12:19 pm
adeel wrote:Q, Is X -ve number??

1, 9x > 10x


i.e if x =1/90

then 1 becomes 1/9 > 1/10

which is true
??
if x = 1/90 then 9x = 9/90 = 1/10
10x = 10/90 = 1/9

and 1/10 < 1/9 so 1 doesnt hold
Charged up again to beat the beast :)

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by arbiter » Sat Aug 22, 2009 12:27 pm
for 9x>10x, x has to be a negative number. thus a is the answer.
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Re: inequality-- data sufficiency

by enniguy » Sat Aug 22, 2009 6:13 pm
adeel wrote:Q, Is X -ve number??

then 1 becomes 1/9 > 1/10
Not True. It becomes 1/10 > 1/9 (Which doesnt hold)