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x is even, is a prime number, and x + y = 11.
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02 Sep 2018, 07:16
02 Sep 2018, 07:16
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x is even, \(\sqrt{x}\) is a prime number, and x + y = 11.
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
\(x\) |
\(y\) |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
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Joined: 10 Apr 2015
Posts: 6218
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Re: x is even, is a prime number, and x + y = 11.
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20 Dec 2018, 07:36
20 Dec 2018, 07:36
1
sandy wrote:
x is even, \(\sqrt{x}\) is a prime number, and x + y = 11.
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
Quantity A |
Quantity B |
\(x\) |
\(y\) |
A)The quantity in Column A is greater.
B)The quantity in Column B is greater.
C)The two quantities are equal.
D)The relationship cannot be determined from the information given.
GIVEN: \(\sqrt{x}\) is a prime number
Some prime numbers: 2, 3, 5, 7, 11, 13, etc
So, some possible values of x are: 2² (aka 4), 3² (aka 9), 5² (aka 25), 7², 11², 13², etc, because \(\sqrt{4}\) is a prime number, \(\sqrt{9}\) is a prime number, \(\sqrt{25}\) is a prime number, etc.
GIVEN: x is even.
We already learned that some possible values of x are: 2² (aka 4), 3² (aka 9), 5² (aka 25), 7², 11², 13², etc
If x is EVEN, then it must be the case that x = 4 (since all other possible x-values are ODD)
GIVEN: x + y = 11
If x = 4, then y = 7
We get:
QUANTITY A: 4
QUANTITY B: 7
Answer: B
Cheers,
Brent
Re: x is even, is a prime number, and x + y = 11.
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01 Jan 2019, 23:09
01 Jan 2019, 23:09
Expert Reply
Just. Know. This. Rule.
2 is the only even prime number
now, if you read that X is even, but it's square root is prime, that means that the square root of x is 2.
because only an even number times itself is ever even.
knowing that, we are certain that X is 4, thus, Y would be 7, which is greater,
The answer is B
2 is the only even prime number
now, if you read that X is even, but it's square root is prime, that means that the square root of x is 2.
because only an even number times itself is ever even.
knowing that, we are certain that X is 4, thus, Y would be 7, which is greater,
The answer is B
