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Remainder when x cube divided by 3

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by saxenashobhit » Thu Jul 07, 2011 5:28 am
What is the remainder X^3 when is divided by 10?

1) x is a multiple of 3.
2) x is a multiple of 5.

Statement (1) by itself is sufficient to answer the question, but statement (2) by itself is not.

Statement (2) by itself is sufficient to answer the question, but statement (1) by itself is not.

Statements (1) and (2) taken together are sufficient to answer the question, even though neither statement by itself is sufficient.

Either statement by itself is sufficient to answer the question.

Statements (1) and (2) taken together are not sufficient to answer the question, requiring more data pertaining to the problem.

Kaplan question 27 - https://www.scribd.com/doc/58999877/GMAT ... et-6-Quant
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Source: — Data Sufficiency |

by Ian Stewart » Thu Jul 07, 2011 5:36 am
saxenashobhit wrote:What is the remainder X^3 when is divided by 10?

1) x is a multiple of 3.
2) x is a multiple of 5.
I assume the question should read: What is the remainder when x^3 is divided by 10?

When you divide a positive integer by 10, the remainder is just the number's units digit. So the question is just asking for the units digit of x^3.

Even using both statements, x could be 15, and x^3 will have a units digit of 5, or x could be 30, and x^3 will have a units digit of 0, so the answer is E.
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by mirantdon » Thu Jul 07, 2011 10:01 am
+1 for E . try pluggin in factor of 3,5 and 15 for the various options i .e , a,b and c resp
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by rishijhawar » Sun Jul 10, 2011 4:05 am
Same here. E.
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by john555 » Sun Jul 10, 2011 8:15 am
E is the only answer.
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