If x is a positive number, what is the
value of x ?
(1) | x - 2 | = 1
(2) x 2 = 4x − 3
OA is E
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vk_vinayak
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Question: x=?grandh01 wrote:If x is a positive number, what is the
value of x ?
(1) | x - 2 | = 1
(2) x 2 = 4x − 3
OA is E
1. |x-2|=1
If (x-2) is positive => x-2=1 => x=3
If (x-2) is negative => 2-x=1 => x=1. INSUF.
2. x^2 - 4x + 3 =0. Solving the equation we get x=3 or x=1. INSUF
Combining: We still get two values for x i.e. x=3 or x=1. INSUF.
Ans E.
- VK
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Brent@GMATPrepNow
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Target question: What is the value of x?grandh01 wrote:If x is a positive number, what is the
value of x ?
(1) | x - 2 | = 1
(2) x 2 = 4x − 3
OA is E
Statement 1: |x - 2| = 1
This yields two cases:
case a: x-2 = 1, which means x=3
case b: x-2 = -1, which means x=1
Since we can't answer the target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x^2 = 4x − 3
Solve for x.
x^2 - 4x + 3 = 0
Factor: (x-3)(x-1) = 0
This yields two cases:
case a: x-3 = 0, which means x=3
case b: x-1 = 0, which means x=1
Since we can't answer the target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 + 2:
Even when we combine the statements, we're left with x=3 or x=1
Since we still can't answer the target question with certainty, the answer is E.
Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
IMO E
Plug in 1 and 3 in statement 1. Both values satisfy. So no concrete answer can be obtained. Therefore equation 1 is not satisfactory.
Factories statement 2. Two factors 1 and 3. Again no single answer? Hence statement 2 is not satisfactory.
Combing both equations no additional info can be obtained. Hence E must be the answer
Plug in 1 and 3 in statement 1. Both values satisfy. So no concrete answer can be obtained. Therefore equation 1 is not satisfactory.
Factories statement 2. Two factors 1 and 3. Again no single answer? Hence statement 2 is not satisfactory.
Combing both equations no additional info can be obtained. Hence E must be the answer
