Answer: 
Step-by-step explanation:
Given: A bag contains 2 black balls, 4 yellow balls and 4 white balls.
Event A is defined as drawing a white ball on the first draw.
Event B is defined as drawing a black ball on the second draw.
P(B|A) is expressed as the conditional probability of occurring B given that A.
i.e. it is the probability of happening B where A is already happended.
If a white ball is drawn at first, then the number of black ball(4) remains unchanged but the total number of balls (10) will become 9.

Then, 
Answer:
9n
Step-by-step explanation:
i mean 9 x n = 9n. straight forward...
The rate charged per hour by each mechanic was: x = 75 $ / hr and y = 115 $ / hr.
<h3>What is a system of equations?</h3>
A system of equations is two or more equations that can be solved to get a unique solution. the power of the equation must be in one degree.
Given;
The first mechanic worked for 20 hours, and the second mechanic worked for 15 hours.
Together they charged a total of $3225.
For this case we have the following variables:
x be the amount of $ / hr that the mechanic obtains 1.
y be the amount of $ / hr obtained by mechanic 2.
An equation to express this would be:
x + y = 190
20x + 15y = 3225
Solving the system of equations we have:
20x + 15(190 -x) = 3225
20x + 2850 - 15x = 3225
5x = 375
x = 75
simililary
y = 190 - x
y = 115
Hence, the rate charged per hour by each mechanic was:
x = 75 $ / hr
y = 115 $ / hr
Learn more about equations here;
brainly.com/question/10413253
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Answer:
Situation 1 is exponential decay. Situation 2 is linear. Situation 3 is exponential growth.
Step-by-step explanation:
Situation 1 is exponential decay because it declined in a non linear way.
600-480=120 480-364=116
Situation 2 is linear because when it declined it has a dependent to another.
400-340=60 340-280=60
Situation 3 is exponential growth because is increases.