Answer:
P (Math or English) = 0.90
Step-by-step explanation:
* Lets study the meaning of or , and on probability
- The use of the word or means that you are calculating the probability
that either event A or event B happened
- Both events do not have to happen
- The use of the word and, means that both event A and B have to
happened
* The addition rules are:
# P(A or B) = P(A) + P(B) ⇒ mutually exclusive (events cannot happen
at the same time)
# P(A or B) = P(A) + P(B) - P(A and B) ⇒ non-mutually exclusive (if they
have at least one outcome in common)
- The union is written as A ∪ B or “A or B”.
- The Both is written as A ∩ B or “A and B”
* Lets solve the question
- The probability of taking Math class 71%
- The probability of taking English class 77%
- The probability of taking both classes is 58%
∵ P(Math) = 71% = 0.71
∵ P(English) = 77% = 0.77
∵ P(Math and English) = 58% = 0.58
- To find P(Math or English) use the rule of non-mutually exclusive
∵ P(A or B) = P(A) + P(B) - P(A and B)
∴ P(Math or English) = P(Math) + P(English) - P(Math and English)
- Lets substitute the values of P(Math) , P(English) , P(Math and English)
in the rule
∵ P(Math or English) = 0.71 + 0.77 - 0.58 ⇒ simplify
∴ P(Math or English) = 0.90
* P(Math or English) = 0.90
