Exponents

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 301
Joined: Tue Apr 22, 2008 6:07 am
Thanked: 2 times

Exponents

by beater » Mon Dec 01, 2008 8:43 am
Is 5^k less than 1,000 ?

(1) 5^(k-1) > 3000
(2) 5^(k-1) = 5^k - 500

Senior | Next Rank: 100 Posts
Posts: 59
Joined: Fri Feb 29, 2008 9:00 am
Thanked: 4 times

by agoyal2 » Mon Dec 01, 2008 11:02 am
IMO D.

From (1)
5^(k-1)>3000
=>5^k>15000

From (2)
5^(k-1) = 5^k - 500
=> 5^k - 5^(k-1) = 500
=>5^(k-1) (5-1) = 500
=>5^(k-1)=125
=>5^k = 725

Looks a little weird after solving it. I might be missing something. Whats the OA?

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Mon Dec 01, 2008 4:00 pm
I think the OA is [spoiler]B)[/spoiler] from the post below

Refer to https://www.beatthegmat.com/tough-one-og ... 16616.html

Senior | Next Rank: 100 Posts
Posts: 75
Joined: Wed Aug 27, 2008 7:19 am
Location: Orlando
Thanked: 6 times

by raajan_p » Mon Dec 01, 2008 5:12 pm
cramya wrote:I think the OA is [spoiler]B)[/spoiler] from the post below

Refer to https://www.beatthegmat.com/tough-one-og ... 16616.html
Cramya - I think the question mentioned in the link that you have provided is slightly different from the question being asked in this post.

The question in ur link says

Is 5^k less than 1000?
(1) 5^k+1 > 3000
(2) 5^k-1 = 5^k-500

If you see the statement 1 here, its says 5^K+1 which is different from the question in this post which is 5^K-1.

Or, I am not sure if I am missing on anything!

Senior | Next Rank: 100 Posts
Posts: 75
Joined: Wed Aug 27, 2008 7:19 am
Location: Orlando
Thanked: 6 times

by raajan_p » Mon Dec 01, 2008 5:13 pm
Having said that, IMO, the answer for this Question would still be D.

Legendary Member
Posts: 2467
Joined: Thu Aug 28, 2008 6:14 pm
Thanked: 331 times
Followed by:11 members

by cramya » Mon Dec 01, 2008 8:10 pm
Raajan,
I could be mistaken here but I think there is a typo in the question posted above.

May be the user meant to say 5^(k+1)>3000 instead of 5 ^ (k-1)