Results 1 to 3 of 3

Math Help - How do you calculate the amount of possible solutions to this two-part lock?

  1. #1
    Newbie
    Joined
    Dec 2012
    From
    st louis
    Posts
    2

    How do you calculate the amount of possible solutions to this two-part lock?

    I am a woodworker, and am designing a two part magnetic/spring lock for my blanket chest. The first part has 3 master buttons (primary buttons A, B, C), and the second part has 11 secondary buttons (1, 2, 3, ....11). What you do first is choose one of the three master buttons. Then out of the secondary buttons, you choose three that will open the lock (and can be pressed in any particular order). So, not only do you have to choose the correct master button, but 3 secondary buttons as well. The master control that you choose stays depressed because of a lever, but each secondary button is spring-loaded so it pushes back out when you release it. The interior of the lock (the guts) is made up of springs, neodymium magnets, steel rods, and blocks of wood (Which really should not matter because it has nothing to do with the math problem). So essentially you are choose 1 out of 3 and 3 out of 11 at the same time. So my question is how do i figure out how many differentpossibilities are there in this lock? for example, A, 1, 2, 3 or C, 4, 9, 11.

    Is there an equation for this problem, or do I have to sit down and figure it out the long way?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123

    Re: How do you calculate the amount of possible solutions to this two-part lock?

    Quote Originally Posted by davidbenjamindix View Post
    I am a woodworker, and am designing a two part magnetic/spring lock for my blanket chest. The first part has 3 master buttons (primary buttons A, B, C), and the second part has 11 secondary buttons (1, 2, 3, ....11). What you do first is choose one of the three master buttons. Then out of the secondary buttons, you choose three that will open the lock (and can be pressed in any particular order). So, not only do you have to choose the correct master button, but 3 secondary buttons as well. The master control that you choose stays depressed because of a lever, but each secondary button is spring-loaded so it pushes back out when you release it. The interior of the lock (the guts) is made up of springs, neodymium magnets, steel rods, and blocks of wood (Which really should not matter because it has nothing to do with the math problem). So essentially you are choose 1 out of 3 and 3 out of 11 at the same time. So my question is how do i figure out how many differentpossibilities are there in this lock? for example, A, 1, 2, 3 or C, 4, 9, 11.

    Is there an equation for this problem, or do I have to sit down and figure it out the long way? <--- that would be a very long way
    1. You have 3 possibilities to choose one master button.

    2. If it is allowed to push the same sec. button multiple times and if it is allowed to push the sec. button in random order (for instance 5, 5, 8 or 9, 2, 6) then you have 11^3 = 1331 possibilities to push 3 sec. buttons.

    3. The max. number of pushing 4 buttons is therefore 3993.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member
    Joined
    Nov 2007
    From
    Trumbull Ct
    Posts
    914
    Thanks
    27

    Re: How do you calculate the amount of possible solutions to this two-part lock?

    Woodworker wants 1 out of 3 master buttons and 3 out of 11 secondary buttons to open lock.

    Possibilities= 3* 11C3 = 3* 165 =495
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Calculate the area of a part of a function
    Posted in the Algebra Forum
    Replies: 2
    Last Post: March 12th 2011, 08:31 AM
  2. Replies: 9
    Last Post: March 16th 2010, 08:38 PM
  3. Replies: 17
    Last Post: June 14th 2009, 05:30 PM
  4. Calculate percentage of unknown amount
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 22nd 2009, 07:53 PM
  5. Combination Lock
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 1st 2007, 03:11 PM

Search Tags


/mathhelpforum @mathhelpforum