March 10, 2023

 Probability

Part B Theoretical Probability

 

When there is a condition in probability, we multiply the numbers together

The chance of arriving at school on time is 9/10, the chance of returning a book late to

the library is 1/9 and the chance of the washroom being closed is 1/15.

What is the probability that Rachel arrives late, returning the book on time and the

washroom being closed on the same date?

 

For examples,

The probability that the bus is on time is 6/7 and the probability that I have my Chromebook is 4/5. Find the probability when

 

7a) The bus is on time, and I have my Chromebook 

 

7b) The bus is late, and I have my Chromebook 

 

7c) The bus is on time, and I don’t have my Chromebook 

 

7d) The bus is late, and I don’t have my Chromebook 

 

The sum of all the probabilities is (7a + 7b + 7c + 7d)

 

 

You are on your own now.

The probability that the Air Canada flight is on time is 8/11 and the probability that my checked bag is not damaged is 9/10. Find the probability when

 

8a) The Air Canada flight is on time and the bag is not damaged 

 

8b) The Air Canada flight is on time and the bag is damaged 

 

8c) 8a) The Air Canada flight is late, and the bag is not damaged 

 

8d) The Air Canada flight is late, and the bag is damaged 

 

The sum of all the probabilities is (8a + 8b + 8c + 8d)

 

 

Now, there are three situations

The probability we will go back to school by the end of March break is 11/12.

The probability Mr. Kwok will teach gym is 1/10.

The probability all the students will get two doses of the Pfizer vaccine is ¾

 

9a) There are eight possible situations here. List them

 

 

9b) Find the probability of each situation

 

 

9c) The sum of all these probabilities is