BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

If m=9^(x−1), then in terms of m, 3^(4x−2) must be which

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 490
Joined: Thu Jul 04, 2013 7:30 am
Location: Chennai, India
Thanked: 83 times
Followed by:5 members

by Uva@90 » Tue Dec 24, 2013 8:54 am
vinni.k wrote:If m=9^(x−1), then in terms of m, 3^(4x−2) must be which of the following?

A. m/3
B. 9m
C. 9m^2
D. m^2/3
E. m^2/9

OA is C

Please explain.

Thanks & Regards
Vinni
Hi Vinni,
Just take some simple value and solve it.

Example Let X =2
m=9^(x−1) => 9^1 => m=9

apply the same to
3^(4x−2) => 3^6 =9*9*9

Now check with the options,
only option that match is C

Regards,
Uva.
Known is a drop Unknown is an Ocean
Top
User avatar
Legendary Member
Posts: 1556
Joined: Tue Aug 14, 2012 11:18 pm
Thanked: 448 times
Followed by:34 members
GMAT Score:650

by theCodeToGMAT » Tue Dec 24, 2013 10:36 am
m = 9^(x-1) = 9^x/9

3^(4x-2) = 9^x*9^x/9 = m * 9^x ==> m * 9 * m = 9 * m^2
[spoiler]
{C}[/spoiler]
R A H U L
Top
Post new topic Post Reply
• Page 1 of 1