The number line above represents which of the following
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- fskilnik@GMATH
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$$?\,\,\,:\,\,\, - 3 < x < 1\,\,\,\, \Leftrightarrow \,\,\,\, - 6 < 2x < 2\,\,\,\,\,\,\,\,\,\,\,\, \Rightarrow \,\,\,\,\,\,\left( {\rm{B}} \right)$$
This solution follows the notations and rationale taught in the GMATH method.
Regards,
Fabio.
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Hi All,
The given Number line shows us a set of numbers from -3 to +1, NOT inclusive. We can TEST VALUES against the 5 answer choices to find the answer that includes JUST that range of numbers...
To start, both Answer A and Answer E include an open-ended range of values, so neither of those is correct.
With X=0, we can eliminate Answer D.
Answer B and C both include all of the values in the Number Line range, but Answer C includes some additional values (such as X = 1.5), that are NOT in the range defined by the Number Line. Eliminate Answer C.
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
The given Number line shows us a set of numbers from -3 to +1, NOT inclusive. We can TEST VALUES against the 5 answer choices to find the answer that includes JUST that range of numbers...
To start, both Answer A and Answer E include an open-ended range of values, so neither of those is correct.
With X=0, we can eliminate Answer D.
Answer B and C both include all of the values in the Number Line range, but Answer C includes some additional values (such as X = 1.5), that are NOT in the range defined by the Number Line. Eliminate Answer C.
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
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- Brent@GMATPrepNow
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We can also solve the question by testing the answer choices
Here's what I mean:
The diagram tells us that x= 0 is a solution to the inequality.
When we check the answer choices, we see that answer choice D (1 < 2x < 3) does NOT have x = 0 as a solution.
When we let x = 0, the inequality becomes 1 < 2(0) < 3. In other words, 1 < 0 < 3
No good! ELIMINATE D
The diagram also tells us that x= 1.5 is NOT a solution to the inequality.
When we check the answer choices, we see that answer choices C and E say that x = 1.5 IS a solution.
C. -9 < 3x < 6. Replace x with 1.5 to get: -9 < 4.5 < 6. Works! Since answer C says that x COULD equal 1.5, we can eliminate answer choice C
E. x > -3. Replace x with 1.5 to get: 1.5 > -3. Works! Since answer E says that x COULD equal 1.5, we can eliminate answer choice E.
We're down to answer choices A and B
The diagram tells us that x= -5 is NOT a solution to the inequality.
When we check the answer choices, we see that answer choice A say that x = -5 IS a solution.
A. x < 1. Replace x with -5 to get: -5 < 1. Works! Since answer A says that x COULD equal -5, we can eliminate answer choice A
By the process of elimination, we're left with...
Answer: B
Cheers,
Brent