Question

Find P(A or B), if the events are disjointed. P(A) = 9/25 P(B) = 9/25

Answer 1

The Probability of A or B that are disjointed events are mutually exclusive.  This means, the probability of the two disjoint events happening can be determine using the formula, P (A or B) = P(A) + P(B)

P (A or B) = P(A) + P(B)
P (A or B) = 9/25 + 9/25
P (A or B) = 18/25

The probability of two disjoint events A or B is 18/25 or 0/72 or 72%.

Answer 2

Answer: $P(A\ or\ B) = \dfrac{18}{25}$

Step-by-step explanation:

We know that when two events are disjoint then their intersection is empty.

if  A and B are disjoint then $P(\cap B)=0$

Also, we know that the probability of getting A or B is given by :

$\text{P(A or B)}=P(A)+P(B)-P(A\cap B)\\\\\Rightarrow\ P(\text{A or B})=\dfrac{9}{25}+\dfrac{9}{25}\\\\\Rightarrow\ P(\text{A or B})=\dfrac{18}{25}$