Nature of Probability

I am clueless on how to work these problems, please help

Find the requested Probablities:
_
P(B) if P (B)= 4/5

Please help me understand this.

I will guess that the first expression is meant to be "the probability of not-B". If so, use the rule related the probabilities of "A" and "not-A". :wink:

I am sorry i dont understand what your trying to say.

the problem is
_
P (B) if P ( B)=4/5



do I have to use s= ?
n=
f=

starkisslove said:

I am sorry i dont understand what your trying to say.
the problem is _
P (B) if P ( B)=4/5
do I have to use s= ?
n=
f=

Click to expand...

Look the problem is with the formatting of your question.
Web pages use HTML to display text on the web.
Spaces do not count. You need to learn LaTeX to desplay mathematics on this site.
What you mean is this \(\displaystyle \overline{B}\) means the complement of \(\displaystyle B\).
So \(\displaystyle P(\overline{B})=1-P(B)\)

Thanks for the information, how do I learn that? LaText

starkisslove said:

I am sorry i dont understand what your trying to say.

Click to expand...

I am asking what the exercise is, using words or standard formatting. In case I have guessed your meaning correctly, I am advising that you review the relationship between the values of the probabilities of "a specific event happens" and "a specific event does not happen". This should look something like "P(yes) + P(no) = 1".

starkisslove said:

do I have to use s= ?
n=
f=

Click to expand...

Since I cannot see your book and since you have not defined these variables, nor their relationship to the given exercise, I'm afraid I cannot answer this question. Sorry.

starkisslove said:

Thanks for the information, how do I learn that? LaText

Click to expand...

To learn LaTeX, use any of the relevant links in the "Forum Help" pull-down menu at the very top of every forum page. To use standard web-safe text-only formatting, follow the directions in either of the formatting links you saw when you read the "Read Before Posting" thread.

Thank you!

I need help on this problem

find the requested probabilities

__
P (B) if P (B) = 4/5

what is the probability of not B if the probability of B is 4/5.

How do I start to understand this problem.

Do I have to start with P(not B)=1-4/5?

starkisslove said:

I need help on this problem

find the requested probabilities

__
P (B) if P (B) = 4/5

what is the probability of not B if the probability of B is 4/5.

How do I start to understand this problem.

Do I have to start with P(not B)=1-4/5?

Click to expand...

Start with

P(B) + P(not B) = 1

Subhotosh Khan said:

starkisslove said:

I need help on this problem

find the requested probabilities

__
P (B) if P (B) = 4/5

what is the probability of not B if the probability of B is 4/5.

How do I start to understand this problem.

Do I have to start with P(not B)=1-4/5?

Click to expand...

Start with

P(B) + P(not B) = 1

Click to expand...

1-4/5=?

then find a comon demominator

4/20-8/20=4/20=1/5

is that the correct way to do this problem? The answer is 1/5