jack0997 wrote:If x ≥ 0.9, which of the following could be the value of (1 /√x)?
(A) 1.02
(B) 1.12
(C) 1.23
(D) 1.45
(E) 2.10
x ≥ 9/10
10x ≥ 9
10 ≥ 9/x
10/9 ≥ 1/x
1/x ≤ 10/9
1/√x ≤ (√10)/3.
The only constraint is that x must be less than (√10)/3.
If B, C, D or E is correct -- implying that one of these answer choices is less than (√10)/3 -- then option
A must also be correct, since it is even SMALLER than B, C, D, or E.
Implication:
Only the SMALLEST answer choice -- option
A -- is viable, implying that none of the other answer choices is less than (√10)/3.
The correct answer is
A.
Last edited by GMATGuruNY on Tue Jun 13, 2017 2:20 am, edited 1 time in total.
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