Katie is twice as old as her sister Mara. The sum of their age is 24.

Discussion in 'Calculator Requests' started by math_celebrity, Sep 15, 2016.

  1. math_celebrity

    math_celebrity Administrator Staff Member

    Let k = Katie's age and m = Mara's age.

    We have 2 equations:

    (1) k = 2m
    (2) k + m = 24

    Substitute (1) into (2)
    (2m) + m = 24

    Combine like terms:
    3m = 24

    Divide each side of the equation by 3 to isolate m
    m = 8

    If m = 8, substituting into (1) or (2), we get k = 16.

     
    Last edited: Dec 21, 2023

Share This Page