Answer: -1
The negative value indicates a loss
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Explanation:
Define the three events
A = rolling a 7
B = rolling an 11
C = roll any other total (don't roll 7, don't roll 11)
There are 6 ways to roll a 7. They are
1+6 = 7
2+5 = 7
3+4 = 7
4+3 = 7
5+2 = 7
6+1 = 7
Use this to compute the probability of rolling a 7
P(A) = (number of ways to roll 7)/(number total rolls) = 6/36 = 1/6
Note: the 36 comes from 6*6 = 36 since there are 6 sides per die
There are only 2 ways to roll an 11. Those 2 ways are:
5+6 = 11
6+5 = 11
The probability for event B is P(B) = 2/36 = 1/18
Since there are 6 ways to roll a "7" and 2 ways to roll "11", there are 6+2 = 8 ways to roll either event.
This leaves 36-8 = 28 ways to roll anything else
P(C) = 28/36 = 7/9
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In summary so far,
P(A) = 1/6
P(B) = 1/18
P(C) = 7/9
The winnings for each event, let's call it W(X), represents the prize amounts.
Any losses are negative values
W(A) = amount of winnings if event A happens
W(B) = amount of winnings if event B happens
W(C) = amount of winnings if event C happens
W(A) = 18
W(B) = 54
W(C) = -9
Multiply the probability P(X) values with the corresponding W(X) values
P(A)*W(A) = (1/6)*(18) = 3
P(B)*W(B) = (1/18)*(54) = 3
P(C)*W(C) = (7/9)*(-9) = -7
Add up those results
3+3+(-7) = -1
The expected value for this game is -1.
The player is expected to lose on average 1 dollar per game played.
Note: because the expected value is not 0, this is not a fair game.
4 dollars and seventy six cents will be the total
Find the area of each shape and add.Let's start with the first semi-circle(half-circle)
If the area of a circle is πr² , then the area of a semi-circle is 1/2πr² where is 22/7 or 3.14, and r is the radius which is 1.8 meters
A=1/2πr²
A=1/2*22/7*1.8*1.8
A=5.09 m²(rounded to nearest hundredth)
Since the semi-circles are two and have the same radius, multiply the area of the first one by two or go through the same process again.
So 5.09 *2=10.18meters square is the area of the two semi-circles
Now, let's find the area of a rectangle which is length times width, where length is 6 meters and width is (1.8+1.8, because 1.8 is half the width)=3.6 meters
A=l*w
A=6*3.6
A=21.6meters square
Therefore the area of the shape is 10.18m²+21.6m²=219.888m²
