Results 1 to 2 of 2

Math Help - what is the number

  1. #1
    Member
    Joined
    Feb 2008
    Posts
    125

    what is the number

    the sum of the digits in the number is 13. the number is 27 more than the number formed by interchanging the tens digit with the one digit. What is the number?
    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
    Quote Originally Posted by mandy123 View Post
    the sum of the digits in the number is 13. the number is 27 more than the number formed by interchanging the tens digit with the one digit. What is the number?
    I'm guessing: You are looking for a two-digit-number(?).

    If so:
    Let x, y denote the digits with x\in\{1, 2, ..., 9\}~\wedge~y\in\{0,1,2,...,9\}

    The original number is 10x + y
    and the number with reverse order of digits is 10y + x

    You have a system of simultaneous equations:

    \left|\begin{array}{rcl}x+y&=&13\\10x+y&=&10y+x+27  \end{array}\right.

    Solve for x and y. I've got x = 8 and y = 5
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: January 16th 2012, 02:21 AM
  2. Replies: 4
    Last Post: April 28th 2011, 07:20 AM
  3. Replies: 2
    Last Post: August 19th 2010, 10:32 PM
  4. Replies: 2
    Last Post: December 18th 2008, 06:28 PM
  5. Replies: 5
    Last Post: October 7th 2008, 01:55 PM

Search Tags


/mathhelpforum @mathhelpforum