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21 Sep 2019, 16:49
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A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
83% (01:01) correct
17%
(01:19)
wrong
based on 759
sessions
History
Date
Time
Result
Not Attempted Yet
What is the value of x ?
(1) \(4^{x + 1} + 4^x = 320\)
(2) \(x^2 = 9\)
DS69402.01
(1) \(4^{x + 1} + 4^x = 320\)
(2) \(x^2 = 9\)
DS69402.01
22 Sep 2019, 10:51
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What is the value of x?
STATEMENT (1)--4^(x+1)+4^x = 320
\(4^x\)*4+\(4^x\) = 320
5*\(4^x\) = 320
\(4^x\) = 64
x = 3
SUFFICIENT
STATEMENT (2)-- \(x^2\) = 9
(x+3)(x-3) = 0
x can be +3, -3
INSUFFICIENT
A is the correct answer
STATEMENT (1)--4^(x+1)+4^x = 320
\(4^x\)*4+\(4^x\) = 320
5*\(4^x\) = 320
\(4^x\) = 64
x = 3
SUFFICIENT
STATEMENT (2)-- \(x^2\) = 9
(x+3)(x-3) = 0
x can be +3, -3
INSUFFICIENT
A is the correct answer
18 Dec 2019, 07:22
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Bookmarks
gmatt1476
What is the value of x ?
(1) \(4^{x + 1} + 4^x = 320\)
(2) \(x^2 = 9\)
(1) \(4^{x + 1} + 4^x = 320\)
(2) \(x^2 = 9\)
Target question: What is the value of x ?
Statement 1: \(4^{x + 1} + 4^x = 320\)
Factor the left side to get: \(4^x(4^1 + 1) = 320\)
Simplify to get: \(4^x(5) = 320\)
Divide both sides by 5 to get: \(4^x = 64\)
Solve: x = 3
Since we can answer the target question with certainty, statement 1 is SUFFICIENT
Statement 2: \(x^2 = 9\)
This equation has two possible solutions: x = 3 and x = -3
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT
Answer: A
Cheers,
Brent
