Results 1 to 2 of 2

Math Help - number of divisors

  1. #1
    Newbie
    Joined
    May 2008
    Posts
    10

    number of divisors

    7a) How many different sums of money can be made from a 2$ bill, a 5$ bill and a 10$ bill
    b) How many different sums of money can be made from the bills in a as well as one more 10$ bill
    c) Why does the situation become much more complicated if another 5$ bill is added

    11. The prime factorization of 540 is 2 X 2 X 3. Find the number of divisors of 12 other than 1 by finding all combination of these numbers

    The prime factorization of 540 is 2 X 2 X 3 X 3 X 3 X 5. Find the other numbers of divisor of 540. Other then 1
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Mr. Edward View Post
    11. The prime factorization of 12 is 2 X 2 X 3. Find the number of divisors of 12 other than 1 by finding all combination of these numbers

    The prime factorization of 540 is 2 X 2 X 3 X 3 X 3 X 5. Find the other numbers of divisor of 540. Other then 1
    If p_1,\ ..,\ p_n are the distinct prime factors of N, with multiplicities k_1,\ ..,\ k_n (number of times they appear in the prime factorisation of N), then any of the numbers:

    l=p_1^{r_1}p_2^{r_2}..p_n^{r_n},\ r_i \in \{0,..,k_i \}

    is a factor of N and different combinations of the r 's give distinct factors.

    There are:

    d(N)=\prod_{i=1}^n (k_i+1)

    different combinations of the r 's, and so distinct factors of N

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Number of positive divisors of n
    Posted in the Number Theory Forum
    Replies: 7
    Last Post: August 17th 2011, 12:04 PM
  2. Number of Positive Divisors
    Posted in the Number Theory Forum
    Replies: 5
    Last Post: March 6th 2011, 04:35 AM
  3. Number of divisors problem
    Posted in the Number Theory Forum
    Replies: 6
    Last Post: December 7th 2010, 07:07 AM
  4. divisors of a number
    Posted in the Number Theory Forum
    Replies: 0
    Last Post: April 8th 2010, 09:34 AM
  5. Number of odd divisors
    Posted in the Discrete Math Forum
    Replies: 4
    Last Post: September 17th 2008, 08:00 AM

Search Tags


/mathhelpforum @mathhelpforum