Respuesta :

Answer:

0.91.

Step-by-step explanation:

We use the formula:

P(a U b) = p(a) + p(b) - p (a ∩ b)     where P(a U b) is p(a or b) and p (a ∩ b) is p  (a and b).

So p(a or b) = 0.78 + 0.66 - 0.53

= 0.91.