.
P(at least one) = P(one) + P(other) - P(both).
To solve the problem, we need to have the probability P(both), but it is not given in the problem.
So, I made an assumption from OUTSIDE of the problem, that these events are independent;
then P(both) =
=
.
Then the answer is
+
-
=
+
-
=
= 0.5536 (rounded).
Solved.