Sum it up. It's called boolean algebra for a reason:

  0 x 0 = 0
  1 x 0 = 0
  1 x 1 = 1

  0 + 0 = 0
  1 + 0 = 1
  1 + 1 = 0 (+ carry)

If you look at the truth tables there, you can see that multiplication is boolean and, and simply addition is xor.

To answer your question:

return (a + b + c) >= 2