Number System 1

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Number System 1

by ranjeet75 » Fri Feb 03, 2012 9:06 pm
If the integer a and n are greater than 1, and the product of the first 8 positive integers is a multiple of a^n, what is the value of a?
1). a^n = 64 2). n = 6

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by Anurag@Gurome » Fri Feb 03, 2012 9:14 pm
ranjeet75 wrote:If the integer a and n are greater than 1, and the product of the first 8 positive integers is a multiple of a^n, what is the value of a?
1). a^n = 64 2). n = 6
The product of the first 8 positive integers is 2 * 3 * 4 * 5 * 6 * 7 * 8 = 2^7 * 3^2 * 5 * 7

(1) a^n = 64
If a = 2 and n = 6, then a^n = 64
If a = 4 and n = 3, then a^n = 64
If a = 8 and n = 2, then a^n = 64
No definite answer; NOT sufficient.

(2) n = 6 implies a^6 and such a number is 2, which appears 6 times in the product of first 8 positive integers. So, a = 2; SUFFICIENT.

The correct answer is B.
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