aazhar
Is x >3
(1) (x-1)² > 4
(2) (x-1)² > 9
Bunuel's solution is perfect, so I won't re-use that strategy.
Another approach is to TEST some values of x.
Target question: Is x >3? Statement 1: (x-1)² > 4 There are several values of x that satisfy statement 1. Here are two:
Case a: x = 10, in which case,
x > 3Case b: x = -10, in which case,
x < 3Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: (x-1)² > 9 There are several values of x that satisfy statement 1. Here are two:
Case a: x = 10, in which case,
x > 3Case b: x = -10, in which case,
x < 3Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined NOTE: since we were able to use the same values of x to show that statements 1 and 2 ALONE are not sufficient, we can re-use them to show that statements 1 and 2 COMBINED are not sufficient
Case a: x = 10, in which case,
x > 3Case b: x = -10, in which case,
x < 3Since we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
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