Is this part of our syllabus? (1 Viewer)

jimmysmith560

Le Phénix Trilingue
Moderator
Joined
Aug 22, 2019
Messages
4,116
Location
Krak des Chevaliers
Gender
Male
HSC
2019
Uni Grad
2022
Since this question appeared in a Mathematics Advanced 2020 trial paper(s), it is part of the syllabus. The working for this question is as follows:

1635397442744.png

I hope this helps! :D
 

specificagent1

Well-Known Member
Joined
Aug 24, 2021
Messages
1,977
Gender
Male
HSC
2021
Since this question appeared in a Mathematics Advanced 2020 trial paper(s), it is part of the syllabus. The working for this question is as follows:

View attachment 32965

I hope this helps! :D
what paper is this? also i did not know this content existed... so screwed. Dont really understand all the notations and the A' stuff, i just do probability by thinking (if that makes sense?)
 

jimmysmith560

Le Phénix Trilingue
Moderator
Joined
Aug 22, 2019
Messages
4,116
Location
Krak des Chevaliers
Gender
Male
HSC
2019
Uni Grad
2022
what paper is this? also i did not know this content existed... so screwed. Dont really understand all the notations and the A' stuff, i just do probability by thinking (if that makes sense?)
This is from the Hunters Hill High School Mathematics Advanced 2020 trial paper.

Since this is a multiple-choice question, your working does not matter as long as you get the correct answer.

The apostrophe is used to denote the complement of a set. A' is all the items that are not in set A.
 

specificagent1

Well-Known Member
Joined
Aug 24, 2021
Messages
1,977
Gender
Male
HSC
2021
This is from the Hunters Hill High School Mathematics Advanced 2020 trial paper.

Since this is a multiple-choice question, your working does not matter as long as you get the correct answer.

The apostrophe is used to denote the complement of a set. A' is all the items that are not in set A.
what does the | mean. So what does P(B|A') geeze can do calculus but not this... rip me
 

5uckerberg

Well-Known Member
Joined
Oct 15, 2021
Messages
562
Gender
Male
HSC
2018
| means what is the probability of something given that the previous event has occurred. Eg, P(B|A) is the probability of B given A. Independent result is when A=A' in terms of probability where A' refers to the complement of the set of A, and usually A=p and A'=1-p which is the complement where p refers to probability, but if they are equal then p=0.5 and this is an even chance which implies results are independent.

and

The independent part is very apparent because the formula can be written like this

I wanted to ask have I made a mistake somewhere?
 
Last edited:

specificagent1

Well-Known Member
Joined
Aug 24, 2021
Messages
1,977
Gender
Male
HSC
2021
| means what is the probability of something given that the previous event has occurred. Eg, P(B|A) is the probability of B given A. Independent result is when A=A' because usually A=p and A'=1-p but if they are equal then p=0.5 and this is an even chance which implies results are independent.

I wanted to ask have I made a mistake somewhere?
ummm could you dumb that down please. I dont really get it
 

jimmysmith560

Le Phénix Trilingue
Moderator
Joined
Aug 22, 2019
Messages
4,116
Location
Krak des Chevaliers
Gender
Male
HSC
2019
Uni Grad
2022
ummm could you dumb that down please. I dont really get it
As was mentioned above, the vertical line "|" means "given that". This means that in the case of P(B | A'), the probability of B depends on that of A', meaning you must be mindful of this in your calculations in order to provide a correct answer.

A more detailed way of solving this question is as follows:

1635399623102.png

Here, the following formula is being used:

1635399684969.png
 

cossine

Well-Known Member
Joined
Jul 24, 2020
Messages
583
Gender
Male
HSC
2017
ummm could you dumb that down please. I dont really get it
@ specificagent it look like Jimmy has answered

Just couple points

- Make sure to remember the definition of conditional probability
- What is the relationship between logic and set theory operators
- When do you use bayes theorem over the definition of conditional probability
 

CM_Tutor

Moderator
Moderator
Joined
Mar 11, 2004
Messages
2,644
Gender
Male
HSC
N/A
Another approach...

Consider a tree diagram:

BoS - tree diagram.png

The question already gives us that .

Following on, let , and note that .

The rule for conditional probability is that


which we need to use interpret the information that has been provided.

We seek the condition for events and to be independent, which requires that


Now, our first piece of information is that :


And, our second piece of information is that :

 

CM_Tutor

Moderator
Moderator
Joined
Mar 11, 2004
Messages
2,644
Gender
Male
HSC
N/A
Some other conditional probability / independence questions

Girraween 2020 q3
Manly Selective 2020 q3, 19
Sydney Girls 2020 q7, 36
Killara 2020 q10
Normanhurst Boys 2020 q10, 20
Sydney Boys 2020 q28
Sydney Grammar 2020 q28
North Sydney Girls 2020 q29
North Sydney Boys 2020 q29

I'm pretty sure these are all on THSC, FYI
 

CM_Tutor

Moderator
Moderator
Joined
Mar 11, 2004
Messages
2,644
Gender
Male
HSC
N/A
And, this question from the Hogwarts Trial...Hogwarts Adv Trial Q 13b.png

The answer is .
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top