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If x is integer that lies between 25 and 500, for how
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31 Jan 2018, 04:40
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Re: If x is integer that lies between 25 and 500, for how
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31 Jan 2018, 04:59
EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMAT\(\frac{X}{20}\) = \(I^{2}\) or X = 20 * \(I^{2}\) The answer choices suggests that we do not have much options, so we can plug in values X = 20 \(1^{2}\)= 20..........out of range X = 20 \(2^{2}\)= 80..........Ok X = 20 \(3^{2}\)= 180..........Ok X = 20 \(4^{2}\)= 320..........Ok X = 20 \(5^{2}\)= 500..........out of range ( if the questions stem says 'inclusive', they it would be valid) We have 3 Integers Answer: B




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Re: If x is integer that lies between 25 and 500, for how
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31 Jan 2018, 04:41



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If x is integer that lies between 25 and 500, for how
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06 Feb 2018, 04:04
EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMAT\(a^2 = \frac{x}{50} > a = \frac{1}{2}\sqrt{\frac{x}{5}}\) \(x = 5k\) As \(25 < x < 500.\) \(k = 9,16,64\)
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Re: If x is integer that lies between 25 and 500, for how
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07 Feb 2018, 04:16
EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMATFor a no. To be a prfct squre. X/20 must have a pair of prime factor ...20= 2*2*5 X must be between 25 to 500 Now we have to check prime factor combination which comes in range.... 2*2*5*2*2/2*2*5 = 80 correct 2*2*5*3*3/2*2*5 = 180 correct 2*2*5*5*5/2*2*5 = 500 incorrect( no must between 25 to 500) So nly 2 numbers are possible Ans.A Sent from my BNDAL10 using GMAT Club Forum mobile app



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If x is integer that lies between 25 and 500, for how
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07 Feb 2018, 04:34
viv007 wrote: EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMATFor a no. To be a prfct squre. X/20 must have a pair of prime factor ...20= 2*2*5 X must be between 25 to 500 Now we have to check prime factor combination which comes in range.... 2*2*5*2*2/2*2*5 = 80 correct 2*2*5*3*3/2*2*5 = 180 correct 2*2*5*5*5/2*2*5 = 500 incorrect( no must between 25 to 500) So nly 2 numbers are possible Ans.A Sent from my BNDAL10 using GMAT Club Forum mobile appHi viv007Why are you considering only primefactor combinations only? Consider the following case x=320, the number x/20 = 16 is a perfect square. Hence x can have 3 values(80,180, and 320). Therefore, Option B(x can take 3 values) should be the answer. Hope that clears your confusion!
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Re: If x is integer that lies between 25 and 500, for how
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07 Feb 2018, 05:31
pushpitkc wrote: viv007 wrote: EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMATFor a no. To be a prfct squre. X/20 must have a pair of prime factor ...20= 2*2*5 X must be between 25 to 500 Now we have to check prime factor combination which comes in range.... 2*2*5*2*2/2*2*5 = 80 correct 2*2*5*3*3/2*2*5 = 180 correct 2*2*5*5*5/2*2*5 = 500 incorrect( no must between 25 to 500) So nly 2 numbers are possible Ans.A Sent from my BNDAL10 using GMAT Club Forum mobile appHi viv007Why are you considering only primefactor combinations only? Consider the following case x=320, the number x/20 = 16 is a perfect square. Hence x can have 3 values(80,180, and 320). Therefore, Option B(x can take 3 values) should be the answer. Hope that clears your confusion! Thank you pushpitkc: Actully 1 more combination pissible i forgot or rather missed it.. I.e. 2*2*5*2*2*2*2/2*2*5 = 320.. Thnku... Sent from my BNDAL10 using GMAT Club Forum mobile app



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If x is integer that lies between 25 and 500, for how
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07 Feb 2018, 11:06
EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMATIf 25<x<500, for how many values of x is \(\frac{x}{20}\) the square of an integer? 25<x<500. Divide this inequality by 20. Therefore \(\frac{25}{20}\)<\(\frac{x}{20}\)< \(\frac{500}{20}\) 1.25<\(\frac{x}{20}\)<25 Only squares in this range are 4, 9 & 16. Therefore Answer: B



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Re: If x is integer that lies between 25 and 500, for how
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12 Feb 2018, 11:57
EgmatQuantExpert wrote: Q.) If x is integer that lies between 25 and 500, for how many values of x is \(\frac{x}{20}\) the square of an integer? A. 2 B. 3 C. 4 D. 5 E. More than 5 Regards, Saquib Quant Expert eGMATHow do we know if the question says X lies between 25 & 500 inclusive or exclusive? Inclusive the answer would be C.



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Re: If x is integer that lies between 25 and 500, for how
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