Very intresting : basic ... try it .

Expert replies

Previous Topic Next Topic

AIM GMAT: Legendary Member; Posts: 857; Joined: Wed Aug 25, 2010 1:36 amFollowed by: 15 members; Thanked: 56 times

by AIM GMAT » Wed Mar 23, 2011 8:11 am

What is the value of M ?

1. M^M = M
2. (1/M)^M = M

Thanks & Regards,
AIM GMAT

Like this post

Source: Beat The GMAT — Data Sufficiency | Wed Mar 23, 2011 8:11 am

kmittal82: Master | Next Rank: 500 Posts; Posts: 324; Joined: Mon Jul 05, 2010 6:44 amFollowed by: 3 members; Location: London; Thanked: 70 times

by kmittal82 » Wed Mar 23, 2011 8:34 am

(1)

m(m-1) = 0

=> m = 0 or m = 1 Not sufficient

(2)
Only m=-1 and m=+1 satisfy this

(1) + (2) gives m = 1

Hence (C)

PS: The only reasonable way I can think of solving (2) is using logarithms, but isnt that beyond the scope of the GMAT?

Like this post

AIM GMAT: Legendary Member; Posts: 857; Joined: Wed Aug 25, 2010 1:36 amFollowed by: 15 members; Thanked: 56 times

by AIM GMAT » Wed Mar 23, 2011 8:36 am

Statement 1 is M to the power M

M^M

Nope no logs required , its very basic . Give it a try.

Thanks & Regards,
AIM GMAT

Like this post

kmittal82: Master | Next Rank: 500 Posts; Posts: 324; Joined: Mon Jul 05, 2010 6:44 amFollowed by: 3 members; Location: London; Thanked: 70 times

by kmittal82 » Wed Mar 23, 2011 8:47 am

AIM GMAT wrote:Statement 1 is M to the power M

M^M

Nope no logs required , its very basic . Give it a try.

Ah right, sorry misread the question

(1) M = +1 and M = -1 both satisfy this

(2) M=-1 and M = +1 both satisfy this

So, (E) ?

Having said that, I have a little confusion... solving (1)
(M^M) - M = 0
M[M^(M-1) - 1 ] = 0

Which means, either M = 0, or M^(M-1) - 1 = 0
Solving further
M^(M-1) = 1
Which means M-1 = 0, or M = 1

This solution doesn't give M=-1, but M=-1 seems like a valid solution for (1)

Like this post

AIM GMAT: Legendary Member; Posts: 857; Joined: Wed Aug 25, 2010 1:36 amFollowed by: 15 members; Thanked: 56 times

by AIM GMAT » Wed Mar 23, 2011 9:08 am

(1) M = +1 and M = -1 both satisfy this

(2) M=-1 and M = +1 both satisfy this

So, (E)

This is correct . I dint consider M= -1 , hence got the wrong answer , very basic indeed important to consider 0 , 1 and -1 while solving by picking up values .

Thanks & Regards,
AIM GMAT

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

559 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review