Is x^2 < x

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Source: — Data Sufficiency |

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by papgust » Thu Jan 21, 2010 9:58 pm
IMO D

We know that X > 0. Is x^2 < x? We could rephrase this question as whether x lies b/w 0 and 1 OR x is > 1? If x is a proper fraction, then x^2 < x. If x is greater than 1, then x^2 > x. So, all we need to know is whether x is a proper fraction or not.

1. 0.1 < x < 0.4

x lies b/w 0 and 1. We can confidently say that x^2 < x. Sufficient.

2. x^3 < x^2

x must lie b/w 0 and 1. Only then x^3 < x^2. Sufficient.

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by prinit » Fri Jan 22, 2010 1:39 pm
1. 0.1 < x < 0.4

In this case x is always a fraction and lies between .1 and .4 , so x^2 will be always less than x

so st(1) is sufficient to answer


2. x^3 < x^2

it is given that x>0, and x^3 < x^2 will be held true for fractions only. So again st(2) is sufficient to answer

choice is D

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by asherman » Fri Jan 22, 2010 4:11 pm
what does the ^ mean in: x^2 ?? I have never seen that symbol...

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by Brent@GMATPrepNow » Fri Jan 22, 2010 4:28 pm
asherman wrote:what does the ^ mean in: x^2 ?? I have never seen that symbol...
It means "to the power of" as in 7^3 (7 cubed) = 7x7x7
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by mehravikas » Fri Jan 22, 2010 6:30 pm
Answer should be D - Reasoning same as above

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by asherman » Sat Jan 23, 2010 12:04 am
ahh... thank you! That is really good to know:) take care, annie