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If k is an integer, what is the value of k? [#permalink]
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24 Mar 2015, 04:44
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If k is an integer, what is the value of k? [#permalink]
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Updated on: 24 Mar 2015, 09:04
Bunuel wrote: If k is an integer, what is the value of k?
(1) 1/5 < 1/(k  1) < 1/2
(2) 3 < (k + 3)/2 < 5 (1) 1/5 < 1/(k  1) < 1/2 Since K is integer (k1) will be an integer so there are two possible values k1=4; K=5 k1=3; K=4 Not Sufficient. (2) 3 < (k + 3)/2 < 5 (K+3)/2 , we can find multiple values of K from this inequality. eg: (K+3)/2=3.5 so K = 4 (K+3)/2=4 so K = 5 (K+3)/2=4.5 so K = 6 Combining A and B , still insufficient. Answer E
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Originally posted by Lucky2783 on 24 Mar 2015, 05:54.
Last edited by Lucky2783 on 24 Mar 2015, 09:04, edited 1 time in total.



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Re: If k is an integer, what is the value of k? [#permalink]
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24 Mar 2015, 08:52
I'm getting answer choice E.
k has to be an integer so
(1) 1/5 < 1/(k1) < 1/2
Then k = 5 or k = 4
1/5 < 1/4 < 1/2 OR 1/5 < 1/3 < 1/2
(2) 3 < (k + 3)/2 < 5
Then k = 4, k = 5, or k = 6
3 < 3.5 < 5 OR 3 < 4 < 5 OR 3 < 4.5 < 5
From (1) we know k is 5 or 4 and from (2) we know it's 4, 5, or 6 and therefore insufficient  E



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Re: If k is an integer, what is the value of k? [#permalink]
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24 Mar 2015, 09:06
MechEGMAT wrote: I'm getting answer choice E.
k has to be an integer so
(1) 1/5 < 1/(k1) < 1/2
Then k = 5 or k = 4
1/5 < 1/4 < 1/2 OR 1/5 < 1/3 < 1/2
(2) 3 < (k + 3)/2 < 5
Then k = 4, k = 5, or k = 6
3 < 3.5 < 5 OR 3 < 4 < 5 OR 3 < 4.5 < 5
From (1) we know k is 5 or 4 and from (2) we know it's 4, 5, or 6 and therefore insufficient  E Right . i overlooked k as 4 and 3 when it is 5 and 4 actually. k1=4 k1=3 Answer E.
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Re: If k is an integer, what is the value of k? [#permalink]
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24 Mar 2015, 12:09
St 1: 1/5 <1/(k1) < 1/2 therefore, 5>k1>2 6>k>3 So k could be 4 or 5 as k is an integer. Not Sufficient. St 2: 3 <(k+3)/2 < 5 therefore, 6 <(k+3) < 10 3<k < 7 So k could be 4 or 5 or 6 as k is an integer.Not Sufficient. Ans: E
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Re: If k is an integer, what is the value of k? [#permalink]
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24 Mar 2015, 19:26
Bunuel wrote: If k is an integer, what is the value of k?
(1) 1/5 < 1/(k  1) < 1/2
(2) 3 < (k + 3)/2 < 5 Statement 1: 1/5 < 1/4 < 1/2 1/5 < 1/3 < 1/2 k= 4 or 5 Insufficient Statement 2: k could be 4,5,6 Insufficient Combined, still insufficient since k could be 4 or 5 Answer: E



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Re: If k is an integer, what is the value of k? [#permalink]
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25 Mar 2015, 00:15
K is int, K=?
1. To satisfy this equation k can be 5 or 4, Not sufficient 2. To satisfy (K+3)/2 can be 3.5,4,4.5; so k can be 4,5,6, Not sufficient
1+2. K can still be 4 or 5 so not sufficient. Hence answer is E
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Re: If k is an integer, what is the value of k? [#permalink]
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30 Mar 2015, 04:28



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Re: If k is an integer, what is the value of k? [#permalink]
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24 Dec 2015, 15:11
agree on E.
1 > k can be 4 or 5. not sufficient. 2 > k can be 4,5, or 6. not sufficient.
1+2  k can be 4 or 5. not sufficient.



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Re: If k is an integer, what is the value of k? [#permalink]
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20 Dec 2017, 20:11
Bunuel niks18How do we simplify St1 as in FightToSurvive approach ? Quote: St 1: 1/5 <1/(k1) < 1/2 therefore, 5>k1>2 6>k>3 So k could be 4 or 5 as k is an integer. Not Sufficient. Can we simplify flip the ratios ? Or since numerator is same, we can associate denominators with same inequality?
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Re: If k is an integer, what is the value of k? [#permalink]
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25 Dec 2017, 09:28
adkikani wrote: Bunuel niks18How do we simplify St1 as in FightToSurvive approach ? Quote: St 1: 1/5 <1/(k1) < 1/2 therefore, 5>k1>2 6>k>3 So k could be 4 or 5 as k is an integer. Not Sufficient. Can we simplify flip the ratios ? Or since numerator is same, we can associate denominators with same inequality? Hi adkikani, here you can cross multiply the ratios because we know k1>0 i.e positive. so on crossmultiplying sign will not be impacted. so 1/(k1)<1/2 =>k1>2=>k>3 and 1/5<1/(k1)=>k1<5=>k<6 Or directly take the reciprocal and invert the inequality sign so 1/5<1/(k1)<1/2 on reciprocating will become 5>k1>2 =>6>k>3 All you need to realize is k1 is positive here




Re: If k is an integer, what is the value of k?
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