Answer:

Step-by-step explanation:
Probability refers to chance of happening of some event.
Conditional probability is the probability of an event A, given that another event B has already occurred.
denote the two boxes.
In box
:
No. of black balls = 1
No. of white balls = 1
In box
:
No. of black balls = 2
No. of white balls = 1
Let B, W denote black and white marble.
So, probability that either of the boxes
is chosen is 
Probability that a black ball is chosen from box
= 
Probability that a black ball is chosen from box 
To find:probability that the marble is black
Solution:
Probability that the marble is black = 
All you have to do is divide the numerator and the denominator by 3 and you get your answer which is 1/6
Answer:
2.5
Step-by-step explanation:
IVE BEEN WATCHING YOUR ACCOUNT STOP STEALING POINTS OR YOUR ACCOUNT WILL BE TERMINATED.
The first is 4
The second one is
4=x-4
-x=-4-4
X=8
⇒To get the difference we subtract.

⇒To get the sum we add.

Goodluck!!