Conditional probability is a measure of the probability of an event given that another event has occurred. If the event of interest is A and the event B is known or assumed to have occurred, "the conditional probability of A given B", or "the probability of A under the condition B", is usually written as P(A|B), or sometimes

.
The conditional probability of event A happening, given that event B has happened, written as P(A|B) is given by

In the question, we were told that there are three randomly selected coins which can be a nickel, a dime or a quarter.
The probability of selecting one coin is

Part A:
To find <span>the probability that all three coins are quarters if the first two envelopes Jeanne opens each contain a quarter, let the event that all three coins are quarters be A and the event that the first two envelopes Jeanne opens each contain a quarter be B.
P(A) means that the first envelope contains a quarter AND the second envelope contains a quarter AND the third envelope contains a quarter.
Thus

</span><span>P(B) means that the first envelope contains a quarter AND the
second envelope contains a quarter
</span><span>Thus

Therefore,

Part B:
</span>To find the probability that all three coins are different if the first envelope Jeanne opens contains a dime<span>, let the event that all three coins are different be C and the event that the first envelope Jeanne opens contains a dime be D.
</span><span>

</span><span>

</span><span>
Therefore,

</span>
1.25 /5
12/5 = 2 with 2 left over
25/5 = 5
2 numbers
1.25 /5 = .25
Each person gets .25 of a pizza
Answer:
Option 3 is right.
Step-by-step explanation:
Reference angle of x is obtained by either 180-x, 180+x. or 360-x depending on the posiiton of terminal whether II quadrant or iv quadrant, or iii quadrant, etc.
In whatever way we find reference angles,
cos will remain cos only and sin will remain sin only there may be only changes in sign.
Of all the ordered pairs given, we find that I, II, and Iv there is a switch over form cos to sine and sin to cos. Hence these options cannot be for reference angles.
III option is 
show that both sign and cos changed sign. This is possible only in III quadrant.
ie reference angle of orignal angle t = 180+t
SO this option is right.
Answer:
x=3 meters
Step-by-step explanation:
step 1
Find the area of the rectangular pool

we have

substitute

step 2
Find the area of rectangular pool including the area of the walkway
Let
x ----> the width of the walkway
we have

substitute

step 3
Find the area of the walkway
To find out the area of the walkway subtract the area of the pool from the area of rectangular pool including the area of the walkway
so

step 4
Find the value of x if the area of the walkway equal the area of the pool
so

Solve for x

Solve the quadratic equation by graphing
The solution is x=3 meters
see the attached figure