How to select random rows where the sum of a column equals to X - MySQL

How i can select random rows of a table when the sum of a column equals to a value ? (MySQL)

    Value : 3

    Name               Price
    ------------------------
    A                  1
    B                  2
    C                  1
    D                  3
    E                  2

I wan to get all possibilities (A + B, D, E + C...).

Thank's Thibeault