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If n is a positive integer and k = 5.1 x 10^n , what is the value of k
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Author:  shaneforu [ 08 May 2010, 08:45 ]
Post subject:  If n is a positive integer and k = 5.1 x 10^n , what is the value of k

If n is a positive integer and k = 5.1 x 10^n , what is the value of k ?

(1) 6,000 < k < 500,000
(2) k^2 = 2.601 * 10^9

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-n-is-a-positive-integer-and-k-5-1-x-10-n-what-is-the-110589.html

Author:  cipher [ 08 May 2010, 11:05 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

shaneforu wrote:
In n is apositive integer and k-5.1 X 10^n

1) 6,000<k<500,000
2) k^2=2.601 X 10^9




I guess you forget to complete the question.. and I think the question is asking value of K
\(K = 5.1 * 10^n\)

1. Sufficient, we can easily see K = 51000, and n = 4, As when n = 3 K will be = 5.1 * 10 ^3 = 5100 and when n = 5 then K = 5.1 * 10 ^5 = 510000

2. Sufficient , \(K = \sqrt{sqr2.601} * \sqrt{sqr(10 ^9)}\)

Hence D

Author:  shaneforu [ 09 May 2010, 19:35 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

nitishmahajan wrote:
shaneforu wrote:
In n is apositive integer and k-5.1 X 10^n

1) 6,000<k<500,000
2) k^2=2.601 X 10^9




I guess you forget to complete the question.. and I think the question is asking value of K
\(K = 5.1 * 10^n\)

1. Sufficient, we can easily see K = 51000, and n = 4, As when n = 3 K will be = 5.1 * 10 ^3 = 5100 and when n = 5 then K = 5.1 * 10 ^5 = 510000

2. Sufficient , \(K = \sqrt{sqr2.601} * \sqrt{sqr(10 ^9)}\)

Hence D


from 2) Can't K be = +51 X 10^4 or -51 X 10^4 there are two possible values here

Author:  cipher [ 10 May 2010, 00:41 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

shaneforu wrote:
nitishmahajan wrote:
shaneforu wrote:
In n is apositive integer and k-5.1 X 10^n

1) 6,000<k<500,000
2) k^2=2.601 X 10^9




I guess you forget to complete the question.. and I think the question is asking value of K
\(K = 5.1 * 10^n\)

1. Sufficient, we can easily see K = 51000, and n = 4, As when n = 3 K will be = 5.1 * 10 ^3 = 5100 and when n = 5 then K = 5.1 * 10 ^5 = 510000

2. Sufficient , \(K = \sqrt{sqr2.601} * \sqrt{sqr(10 ^9)}\)

Hence D


from 2) Can't K be = +51 X 10^4 or -51 X 10^4 there are two possible values here



st2 can be written as

\(K = \sqrt{2.601} * \sqrt{(10 ^9)}\) = \(\sqrt{2601} * \sqrt{(10 ^6)} = 51 * (10 ^3) = 5.1 * (10^4) [ As K = 5.1 * 10 ^n ]\)

Now if n =4 then K will always be positive and thats why we ruled out the -ve value of K

Author:  dixitraghav [ 16 May 2010, 09:53 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

D
both the equations are sufficient to find the value of K

Author:  ying [ 08 Jun 2010, 21:30 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

nitishmahajan wrote:

Now if n =4 then K will always be positive and thats why we ruled out the -ve value of K


Even if n<0, k is always > 0.

Author:  Bunuel [ 24 Dec 2016, 07:48 ]
Post subject:  Re: If n is a positive integer and k = 5.1 x 10^n , what is the value of k

If n is a positive integer and k = 5.1 * 10^n, what is the value of k ?

As n is a positive integer then k could be: 51, 510, 5,100, 51,000, ... Also note that no matter the value of n, k is always a positive number.

(1) 6,000 < k < 500,000 --> only one number from above is in this range: 51,000. Sufficient.

(2) k^2 = 2.601 * 10^9 --> we can solve quadratics to get two values of k positive and negative, but since given that k is positive then only the positive value of k will be valid. Sufficient.

Answer: D.

OPEN DISCUSSION OF THIS QUESTION IS HERE: if-n-is-a-positive-integer-and-k-5-1-x-10-n-what-is-the-110589.html

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