Question

Events A and B are disjointed. P(A) = 4/11; P(B) = 3/11, P(A and B)= 2/11 . Find P(A or B).

Answer 1

5/11

How I got my answer:

For overlapping events, you would subtract P(A and B) from the sum of P(A) and P(B).

In this case, you would do 4/11 + 3/11, which equals 7/11 minus 2/11, which equals 5/11.

Answer 2

`P(A\:or\:B)=(7)/(11)`

Explanation:

If the two events are disjoint, then P(A or B)=P(A)+P(B).

We were given that:

`P(A)=(4)/(11)`

and

`P(B)=(3)/(11)`

This implies that:

`P(A\:or\:B)=(4)/(11)+(3)/(11)`

We simplify the right hand side to obtain:

`P(A\:or\:B)=(4+3)/(11)`

`P(A\:or\:B)=(7)/(11)`