ds:inequality

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ds:inequality

by arjunshn » Sat Apr 16, 2011 2:20 am
If k is an integer, what is the value of k?
(1) (k - 1)(k - 3) < 0
(2) (k - 5)(k - 1)(k - 3)(k - 6) < 0

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by pemdas » Sat Apr 16, 2011 2:53 am
k=integer, find k-?
st(1) two options k-1<0 and k-3>0 {k<1 and k>3} OR k-1>0 and k-3<0 {k>1 and k<3} -> the only vaiable solution 1<k<3 i.e. k=2 Sufficient
st(2) (k - 5)(k - 1)(k - 3)(k - 6) < 0, let's try plugging in k=2 -> (2 - 5)(2 - 1)(2 - 3)(2 - 6) < 0 Sufficient;

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arjunshn wrote:If k is an integer, what is the value of k?
(1) (k - 1)(k - 3) < 0
(2) (k - 5)(k - 1)(k - 3)(k - 6) < 0

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by arjunshn » Sat Apr 16, 2011 4:08 am
But in 1st case we also get k<1 and k>3..thus it can be any number in this range..so isnt it wrong jus chosing k>1 and k<3?

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by pemdas » Sat Apr 16, 2011 4:11 am
k must have ONLY one value, an integer value. Try different values for k -> (k - 1)(k - 3) < 0
arjunshn wrote:But in 1st case we also get k<1 and k>3..thus it can be any number in this range..so isnt it wrong jus chosing k>1 and k<3?

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by arjunshn » Sat Apr 16, 2011 4:23 am
thank you..