Question

*HELP PLEASE*

Events A and B are disjoint.
P(A) = 40/61 and
P(B) = 2/61.
FIND P(A or B)

Answer 1

If two events are disjoint (i.e. mutually exclusive) they cannot both occur and so we can determine probabilties by simple addition:


`P(AorB)=P(A)+P(B)`

`P(AorB)=(40)/(61)+(2)/(61)`

`P(AorB)=(42)/(61)`

`P(AorB)\approx 68.8\%`

A more complete answer would use a joint probability table but that's difficult to type out/format correctly here.