Let a, b, c be events such that p(a) = 0.2 , p(b) = 0.3, p(c) = 0.4

find the probability that at least one of the events a and b occurs if

(a) a and b are mutually exclusive;
(b) a and b are independent.
find the probability that all of the events a, b, c occur if
(a) a, b, c are independent;
(b) a, b, c are mutually exclusive.

At least  one of the events A and B occurs:

(a) 0.5

(b) 0.44

All of the events A, B, C occur:

(a) 0.024

(b) 0

Step-by-step explanation:

Given:

P(A) = 0.2, P(B) = 0.3, P(C) = 0.4

At least  one of the events A and B occurs:

(a) If A and B are mutually exclusive events, then their intersection is 0.

Probability of at least one of them occurring means either of the two occurs or the union of the two events. Therefore,

(b) If A and B are independent events, then their intersection is equal to the product of their individual probabilities. Therefore,

All of the events A, B, C occur together:

(a) All of the events occurring together means the intersection of all the events.

If A, B, and C are independent events, then their intersection is equal to the product of their individual probabilities. Therefore,

(b) If A, B, and C are mutually exclusive events means events A, B, and C can't happen at the same time. Therefore, their intersection is 0.

step-by-step explanation:

i have done this all on a piece of paper but idk how to put it on here cuz it needs to be drawn

78.59 is the mean

step-by-step explanation: