1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Integers Modulo n

  1. Apr 9, 2004 #1
    I understand how to solve: a=12mod7 => a = 5, I think, however,
    how do you solve for a=7mod12 ?
    Stumped :eek:
     
  2. jcsd
  3. Apr 9, 2004 #2

    matt grime

    User Avatar
    Science Advisor
    Homework Helper

    When you say solve, is what you mean is given an integer p find an integer q with 0<=q<n and p==q mod(n) as 7 is between 0 and 11 it solves itself, if you will.
     
  4. Apr 9, 2004 #3
    Do not understand your response:

    if a=12mod7 yields a=5: 5 is the remainder however,
    if a=7mod12 what is a? & how do I get there?

    Thanks,

    JimK
     
  5. Apr 9, 2004 #4

    matt grime

    User Avatar
    Science Advisor
    Homework Helper

    How ling did you spend trying to understand the answer I gave? a=7 is, shall we say, in the reduced form. The remainder after dividing 7 by 12 is 7.

    As it stands, when you say solve a=p mod(n) you are not using a well defined phrase. What you might ought to mean is find the remainder on division by n of p, but that isn't immediately obvious from what you wrote. That is, and I realize I'm just restating what I orginally wrote, find the a with 0<=a<n that is the remainder on dividing by n of p. If a is already in that range you are done.

    Remember these aren't equals signs, they are equivalences.
     
  6. Apr 20, 2004 #5

    Gokul43201

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    12 mod 7 == 5 bacause 5 is the difference when you find the largest multiple of 7 that is less than 12 (i.e., 7 itself).

    To find what 7 mod 12 is, note that 0 is a multiple of any number. So, now, 0 is the largest multiple of 12 that lies just below 7, and the remainder is 7 itself.

    This should be obvious from the reasoning that you are asking what hour 7 refers to on a 12 hr clock.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Integers Modulo n
  1. Integers Modulo (Replies: 2)

  2. The Integers Modulo n (Replies: 9)

Loading...