question about  combinatorical
here is task


    How many ways are there to choose from the set {1, 2, . . . , 100} three distinct
    numbers so that their sum is even?
first of all  sum of three numbers  is even if only if

    1.all number is even
    2.two of them is odd and one is even
i know that  

    (n)   =  n!/(k!*(n-k)!   
    (k)   

and can anybody help me to solve this problem

question about  combinatorical
===

here is task


    How many ways are there to choose from the set {1, 2, . . . , 100} three distinct
    numbers so that their sum is even?
first of all  sum of three numbers  is even if only if

    1.all number is even
    2.two of them is odd and one is even
i know that  

    (n)   =  n!/(k!*(n-k)!   
    (k)   

and can anybody help me to solve this problem
