OG 12 DS

This topic has expert replies
Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

OG 12 DS

by ketkoag » Wed Aug 26, 2009 1:21 am
If n is a positive integer and k = 5.1 * 10^n, what is the
value of k ?
(1) 6,000 < k < 500,000
(2) k^2 = 2.601 * 10^9

answer given is D.. please lemme know why B is sufficient.. value of k could be negative or positive..

Junior | Next Rank: 30 Posts
Posts: 13
Joined: Sat Jul 11, 2009 8:37 pm
Thanked: 2 times

by ShikenO/kau » Wed Aug 26, 2009 1:41 am
If n is a positive integer and k = 5.1 * 10^n, what is the
value of k ?
(1) 6,000 < k < 500,000
(2) k^2 = 2.601 * 10^9

Statement I:
IF n= 3
k = 5100
If n =4
k = 51000
If n=5
k=510000
From statement I, we get to know that 6,000 < k < 500,000
So n=4 and k =51000
Statement I is sufficient.

Statement II:
k^2 = 2.601 * 10^9

In the question k= 5.1 * 10^n
so K cannot be negative as it is the product of two positive numbers.

So K = 51000

So Statement II is also sufficient.

And the answer is D.

Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

by ketkoag » Fri Aug 28, 2009 1:21 am
ShikenO/kau wrote:If n is a positive integer and k = 5.1 * 10^n, what is the
value of k ?
(1) 6,000 < k < 500,000
(2) k^2 = 2.601 * 10^9

Statement I:
IF n= 3
k = 5100
If n =4
k = 51000
If n=5
k=510000
From statement I, we get to know that 6,000 < k < 500,000
So n=4 and k =51000
Statement I is sufficient.

Statement II:
k^2 = 2.601 * 10^9

In the question k= 5.1 * 10^n
so K cannot be negative as it is the product of two positive numbers.

So K = 51000

So Statement II is also sufficient.

And the answer is D.
Ahh, thanks.. i missed the given value of k in the question.. K cannot be negative..
what a silly mistake!! :wink: