(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?
Very intresting : basic ... try it .
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Source: Beat The GMAT — Data Sufficiency |
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kmittal82
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Ah right, sorry misread the questionAIM GMAT wrote:Statement 1 is M to the power M
M^M
Nope no logs required , its very basic . Give it a try.
(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)
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AIM GMAT
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(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
AIM GMAT
