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Guide 1: Chapter 4: Question: 11 (pg. 58, 4th edition)

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lionelpq
 Post subject: Guide 1: Chapter 4: Question: 11 (pg. 58, 4th edition)
 Post Posted: Tue Jun 29, 2010 5:25 am 
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Students


Posts: 5
The answer to question 11 says "As we learned in Chapter 1, there are (4+1)(1+1)=10 different factors of 2^4*3." What is this formula refered to in Chapter 1 that gets us to 10? I could not find it.

Thanks!
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phoenix.rkchr
 Post subject: Re: Guide 1: Chapter 4: Question: 11 (pg. 58, 4th edition)
 Post Posted: Tue Jun 29, 2010 6:03 am 
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Students


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lionelpq wrote:
The answer to question 11 says "As we learned in Chapter 1, there are (4+1)(1+1)=10 different factors of 2^4*3." What is this formula refered to in Chapter 1 that gets us to 10? I could not find it.

Thanks!


The formula to find the total number of factors of any number N is:

(a+1)(b+1)(c+1)........

where a, b, c, ..... are the powers of prime factors of the number N.

e.g. N = 72
prime factors of 72= 2X2X2X3X3 = 2^3 X 3^2

here a = 3 and b = 2

So number of factors of 72 = (3+1)(2+1) = 12
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lionelpq
 Post subject: Re: Guide 1: Chapter 4: Question: 11 (pg. 58, 4th edition)
 Post Posted: Tue Jun 29, 2010 8:48 am 
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Apreciate it. Thanks
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tim
 Post subject: Re: Guide 1: Chapter 4: Question: 11 (pg. 58, 4th edition)
 Post Posted: Thu Jul 08, 2010 1:44 pm 
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Location: Southwest Airlines, seat 21C
Thanks, Phoenix..

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