In exercises 3-6, events a and b are disjoint. find p(a or b).
3. p(a)=0.3, p(b)=0.1
5. p(a)= 1/3, p(b)=1/4
also if you can be explain how to do these problems i'm home schooled and don't understand at all

Problem 3

Disjoint events are two (or more) events that cannot happen at the same time. An example would be flipping heads and tails at the same time with the same coin. Another example is selecting an ace of spades and selecting an ace of diamonds, when you only select one card.

In general notation, P(A and B) = 0 if and only if A and B are disjoint.

P(A or B) = P(A) + P(B) - P(A and B)

P(A or B) = 0.3 + 0.1 - 0

Problem 5

Same idea, but different numbers

P(A or B) = P(A) + P(B) - P(A and B)

P(A or B) = 1/3 + 1/4 - 0

P(A or B) = 4/12 + 3/12 - 0

step-by-step explanation:

cats

all three statements are true

step-by-step explanation:

a shipping fee of 5% is charged online with every item purchased online

first let's just take each option and calculate them based on this, to see if the answers matched

keith buys a 40 dollar book

40 x 0.05 = 2

therefore there will be a two dollar fee on keith's book

40 + 2 =42

the first statement is true

a chair costs $80

80 x 0.05 = 4

80 + 4 = 84

the second statement is true

george buys a 20 dollar calculator

20 x 0.05 = 1

20 + 1 = 21

the third statements are true

all three statements are true