If a rational number r satisfies 0 < r < 1, which one is the minimum among the following choices?

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[GMAT math practice question]

If a rational number r satisfies 0 < r < 1, which one is the minimum among the following choices?

A. r
B. -r
C. -1/r
D. -r^2
E. -1/r^2
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Max@Math Revolution wrote:
Thu Aug 06, 2020 2:38 am
[GMAT math practice question]

If a rational number r satisfies 0 < r < 1, which one is the minimum among the following choices?

A. r
B. -r
C. -1/r
D. -r^2
E. -1/r^2
IS IT E?

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We can substitute in a number satisfying the condition.
Assume r = 1/2.
Then -r = -1/2, -1/r = -2, -r^2 = -1/4 and -1/r^2 = -4
Thus -1/r^2 = -4 is the minimum number.

Therefore, E is the correct answer.

Answer: E