Answer: the player answered 30 questions correctly.
Step-by-step explanation:
Let x represent the number of questions that the player answered correctly.
Let y represent the number of questions that the player answered incorrectly.
The number of questions that the player answered is 40. It means that
x + y = 40- - - - - - - - - - -1
The score on the trivia game is obtained by subtracting the number of incorrect answers from twice the number of correct answers. If the player obtained a score of 50, It means that
2x - y = 50
y = 2x - 50
Substituting y = 2x - 50 into equation 1, it becomes
x + 2x - 50 = 40
3x - 50 = 40
3x = 40 + 50 = 90
x = 90/3
x = 30
Answer: 0.31
Step-by-step explanation:
Let A denotes the event that the students report drinking alcohol and B denotes the students report using some type of tobacco product .
Given : P(A) =0.84 ; P(B)=0.33 and P(A∪B)=0.86
We know that 
Then, the probability that the student both drunk alcohol and used tobacco in the past month is given by :-

Hence, the probability that the student both drunk alcohol and used tobacco in the past month = 0.31
For monthly membership, the cost must be less than $325. We can set up an inequality:-
100 + 30x < 325 where x = number of months of membership
Solving -
30x < 325-100 = 225
x < 225 / 30
x < 7.5 months
The answer is 7 months.
Answer:
8 points
Step-by-step explanation:
Given that there are 4 teams and Each team plays each of the other teams exactly once, then each team plays 3 matches. The possible points after 3 matches are:
0: 3 lost
1: 2 lost, 1 tied
2: 2 tied, 1 lost
3: 3 tied
4: 1 won, 1 lost, 1 tied
5: 1 won, 2 tied
6: 2 won, 1 lost
7: 2 won, 1 tied
9: 3 won