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.
Answer: 2 buses and 4 vans would be needed
Step-by-step explanation:
Let x represent the number of buses that would be needed.
Let y represent the number of vans that would be needed.
There will be six drivers, and two different types of vehicles. This means that
x + y = 6
142 students are going on a field trip. A bus can hold 51 people while a van can hold 10. This means that
51x + 10y = 142 - - - - - - - - - - - 1
Substituting x = 6 - y into equation 1, it becomes
51(6 - y) + 10y = 142
306 - 51y + 10y = 142
- 51y + 10y = 142 - 306
- 41y = - 164
y = - 164/ - 41
y = 4
x = 6 - y = 6 - 4
x = 2
Answer:
The correct answer is 2x - y - 1 = 0
Step-by-step explanation:
To find this, use the ordered pair (1, 1) in any of the equations. If it results in a true statement then this can be an equation.
2x - y - 1 = 0
2(1) - (1) - 1 = 0
2 - 1 - 1 = 0
0 = 0 (TRUE STATEMENT)
