Answer:
0
Step-by-step explanation:
given that we roll a fair die repeatedly until we see the number four appear and then we stop.
the number 4 can appear either in I throw, or II throw or .... indefinitely
So X = the no of throws can be from 1 to infinity
This is a discrete distribution countable.
Sample space= {1,2,.....}
b) Prob ( 4 never appears) = Prob (any other number appears in all throws)
= 
where n is the number of throws
As n tends to infinity, this becomes 0 because 5/6 is less than 1.
Hence this probability is approximately 0
Or definitely 4 will appear atleast once.
The formula of a trapezoid is the sum of the both bases multiplied by the height then divided by 2.
Answer: 28.26
Step-by-step explanation:
What your looking for is called the annulus (or the difference of two concentric circles). You can find the annulus by subtracting the area of the inner circle from the area of the outer circle. Volume of a circle= πr²
You are given the diameter in these problems, so you need radius.
For the first circle (8 in one) :
8/2=4 r=4
A=3.14(4)²
A=50.24
For the second one (10 in one) :
10/2=5 r=5
A=3.14(5)²
A=78.5
To find the measure of the annulus, you subtract those numbers, getting 28.26