For all integers n, n* = n(n-1). What is the value of x*?
(1) x* = x
(2) (x-1)* = x-2
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Value of x*
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From (1) x(x-1) = x
Or x(x-2) = 0.
Or x = 0 or 2.
Since we do not get a unique value of x (1) is not sufficient.
From (2) (x-1)*(x-2) = (x-2).
Or (x-1)*(x-2)-(x-2) = 0.
Or (x-2)*(x-2) = 0.
Or x = 2.
So (2) alone is sufficient.
The correct answer is (B).
Or x(x-2) = 0.
Or x = 0 or 2.
Since we do not get a unique value of x (1) is not sufficient.
From (2) (x-1)*(x-2) = (x-2).
Or (x-1)*(x-2)-(x-2) = 0.
Or (x-2)*(x-2) = 0.
Or x = 2.
So (2) alone is sufficient.
The correct answer is (B).
Rahul Lakhani
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Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
