What is the square root of x?
1) The cube root of x is 81.
2) The 6th root of x is 9.
Pl. help me with this confusing question.
What is the square root of x?
This topic has expert replies
The first data is usable because it helps to find the number ,since it is odd root
Other information is talking about 6th root ( which is even)
So your original number could be negative or positive
All in all, the answer is A
Other information is talking about 6th root ( which is even)
So your original number could be negative or positive
All in all, the answer is A
I think the second one is also usable since '9' is positive and its a root of a number, so the base number should be positive.soudeh wrote:The first data is usable because it helps to find the number ,since it is odd root
Other information is talking about 6th root ( which is even)
So your original number could be negative or positive
All in all, the answer is A
Experts, need help...
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Hi aaron1981,
This question is a 'lift' of an OG question:
GMAT2017: pg. 276, Q240
GMAT2018: pg. 272, Q240
When dealing with this type of math, you have to be clear on the difference between:
X^2 = 9 ... this has two solutions: +3 and -3
(root9) ... this has one solution: +3
When a question asks for the square root of a number, there's only one answer: the POSITIVE one. In this question, both of the Facts give you enough information to determine the value of X, so you could then determine the square root of X. Thus, both Facts are SUFFICIENT
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
This question is a 'lift' of an OG question:
GMAT2017: pg. 276, Q240
GMAT2018: pg. 272, Q240
When dealing with this type of math, you have to be clear on the difference between:
X^2 = 9 ... this has two solutions: +3 and -3
(root9) ... this has one solution: +3
When a question asks for the square root of a number, there's only one answer: the POSITIVE one. In this question, both of the Facts give you enough information to determine the value of X, so you could then determine the square root of X. Thus, both Facts are SUFFICIENT
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
GMAT/MBA Expert
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Statement One Alone:aaron1981 wrote:What is the square root of x?
1) The cube root of x is 81.
2) The 6th root of x is 9.
The cube root of x is 81
We can create the equation:
∛x = 81
x = 81^3 = 3^12, so the square root of x is 3^6.
Statement one alone is sufficient to answer the question.
Statement Two Alone:
The 6th root of x is 9.
We can create the equation:
^6√x = 9
x = 9^6 = 3^12
So the square root of x is 3^6.
Answer: D
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