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# If x and y are different integers, both divisible by 5, then which is

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Math Expert
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If x and y are different integers, both divisible by 5, then which is  [#permalink]

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01 Dec 2015, 03:59
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5% (low)

Question Stats:

92% (00:54) correct 8% (00:37) wrong based on 100 sessions

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If x and y are different integers, both divisible by 5, then which is not necessarily true?

(A) x^2 + y^2 is divisible by 5

(B) x - y is divisible by 5

(C) xy is divisible by 5

(D) x + y is divisible by 5

(E) x + y is divisible by 10

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Re: If x and y are different integers, both divisible by 5, then which is  [#permalink]

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01 Dec 2015, 04:07
x = 5k_1
y = 5k_2

A) x^2 + y^2 = 25(K_1^2 + K_2^2) --> Divisible by 5
B) x - y = 5(K_1 - K_2) --> Divisible by 5
C) xy = 25(K_1*K_2) --> Divisible by 5
D) x + y = 5(K_1 + K_2) --> Divisible by 5
E) x + y = 5(K_1 + K_2) --> Not divisible by 10 always

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Re: If x and y are different integers, both divisible by 5, then which is  [#permalink]

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01 Dec 2015, 12:45
1
Bunuel wrote:
If x and y are different integers, both divisible by 5, then which is not necessarily true?

(A) x^2 + y^2 is divisible by 5

(B) x - y is divisible by 5

(C) xy is divisible by 5

(D) x + y is divisible by 5

(E) x + y is divisible by 10

The best way to solve this problem is plugging in some values of x and y

Let x = 5 and y = 10

(A) x^2 + y^2 is 125 (25+100) which is divisible by 5

(B) x - y is -5 ( 5 - 10 ) which is divisible by 5

(C) xy is 50 (5*10) which is divisible by 5

(D) x + y is 15 ( 5 + 10 ) which is divisible by 5

(D) x + y is 15 ( 5 + 10 ) which is not divisible by 10

Hence IMHO (E)
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Re: If x and y are different integers, both divisible by 5, then which is  [#permalink]

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02 Dec 2015, 23:05
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Hi All,

This question can be solved rather easily by TESTing VALUES (the approach that Abhishek009 used). The prompt never states that X and Y are positive though, so you don't have to use two different positive multiples of 5. You COULD use...

X = 0
Y = 5

That would make the calculations even easier/faster and still provide the correct answer to the question.

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Re: If x and y are different integers, both divisible by 5, then which is  [#permalink]

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16 Mar 2016, 10:35
Here we can choose 5,10 and 5,15 as the possible cases
and apart of E all satisfy the requirement
hence E
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Re: If x and y are different integers, both divisible by 5, then which is  [#permalink]

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04 Feb 2019, 00:01
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Re: If x and y are different integers, both divisible by 5, then which is   [#permalink] 04 Feb 2019, 00:01
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