For an event E , P(E) + P(E`) = q , then

(a) 0<q < 1

(b) 0 < q <1

(c) 0 < q < 1

(d) none of these

Let E be any event and E' be its complement.

We know that P(E') = 1 – P(E)

⇒ P(E) + P(E') = 1

⇒ q = 1

∴ option (d) is correct.