Answer:
The answer is B, I know this because I just took a test with this question lol
If 12 correct answers constitute a passing grade on a 20-item true-false exam, the probability that someone will pass is 1/2 if they are guessing.
What is meant by probability?Probability is synonymous with possibility. It is a mathematical branch that deals with the occurrence of a random event. The value ranges from zero to one. Probability has been introduced in mathematics to predict the likelihood of events occurring. Probability = the number of possible paths to success. The total number of possibilities For example, the probability of flipping a coin and getting heads is 12, because there is only one way to get a head and there are two possible outcomes.Therefore,
Let X denote the number of correctly answered questions out of a total of 20.
Bernoulli trails are formed by repeated coin tosses. Because the "head" on a coin represents the correct answer and the "tail" represents the incorrect answer, the questions that are correctly answered are Bernoulli trials.
[tex]$&\therefore \mathrm{p}=\frac{1}{2} \\[/tex]
[tex]&\therefore \mathrm{q}=1-\mathrm{p}=1-\frac{1}{2}=\frac{1}{2}[/tex]
X follows a binomial distribution with n = 20 and p = 1/2
[tex]&\therefore P(X=x)={ }^n C_x q^{n-x} p^x \\[/tex]
[tex]&={ }^{20} C_x\left(\frac{1}{2}\right)^{20-x} \cdot\left(\frac{1}{2}\right)^x \\[/tex]
[tex]&={ }^{20} C_x\left(\frac{1}{2}\right)^{20}[/tex]
P ( at least 12 questions answered correctly )= P (X ≥ 12)
[tex]&=\mathrm{P}(\mathrm{X}=12)+\mathrm{P}[/tex][tex](\mathrm{X}=13)+\ldots+\mathrm{P}(\mathrm{X}=20) \\[/tex]
[tex]&={ }^{20} \mathrm{C}_{12}\left(\frac{1}{2}\right)^{20}+{ }^{20}[/tex][tex]\mathrm{C}_{13}\left(\frac{1}{2}\right)^{20}+\ldots+{ }^{20}[/tex][tex]\mathrm{C}_{20}\left(\frac{1}{2}\right)^{20} \\[/tex]
[tex]&=\left(\frac{1}{2}\right)^{20} \cdot\left[{ }^{20} \mathrm{C}_{12}+{ }^{20} \mathrm{C}_{13}+\ldots+{ }^{20} \mathrm{C}_{20}\right][/tex]
Hence, If 12 correct answers constitute a passing grade on a 20-item true-false exam, the probability that someone will pass is 1/2 if they are guessing.
The complete question is:
In an examination, 20 questions of true-false type are asked. Suppose a student tosses a fair coin to determine his answer to each question. If the coin falls heads, he answers 'true', if it falls tails, he answers 'false'. Find the probability that he answers at least 12 questions correctly.
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Helppp me plssss! ASAP
Answer:
140 ft.
Step-by-step explanation:
first find the area of the rectangle
16 x 8 = 128
Area: 128
then find the area of the triangle
Base: 4
Height: 6
Area: 12
Then all u need to do is add
12 + 128 = 140
Which transformation of a shape may result in a new shape not congruent with the original shape?
O dilation
O reflection
O rotation
O translation
Answer:
dilation
Step-by-step explanation:
dilation will make the shape larger or smaller which will change the shape.
I would really appreciate some help. Thanks!
Seth has game and education apps on his tablet. He noticed that he has 5 game apps for every 2 education apps. Which of the following is another way to write this ratio?
A. 2:3
B. 2:5
C. 3:2
D. 5:2
Answer:
D
Step-by-step explanation:
the question says that he has 5 to 2 and if you put it in a fraction you cant reduce it so therefore the answer has to be 5:2
Answer:
D. 5:2
Step-by-step explanation:
He has 5 games so 5: for every 2 school apps so 5:2
The correct Standard Form of the equation y=−1/3x+23/9
Answer:
3x + 9y = 23
Step-by-step explanation:
This table gives a few (x, y) pairs of a line in the coordinate plane. What is the y-intercept of the line?
Answer:
The Y-intercept is the Y value when X = 0.
Find the change in X:
-56 to -42 = 14
-42 to -28 = 14
The X value changes by 14.
For every change in X the Y change:
66-58 = 8
58-50 = 8
For X to get from -28 to 0 would be 2 more changes:
-28 +14 = -14
-14 + 14 = 0
2 more changes of Y would be:
50-8 = 42
42-8 = 34
So when X = 0, Y = 34
The Y-intercept would be (0,34)
Step-by-step explanation:
like if it helps <3
The regular admission price for an amusement park is $72. For a group of 15, or more, the admission price is reduce by $25 per person. How many people need to be in a group to save $500?
=========================================
Explanation:
x = number of people
Without the discount, each person pays $72, so the total cost is 72x dollars if x people go through the gate individually.
Now applying the group discount, those x people pay 72-25 = 47 dollars each. Meaning the total cost is now 47x. Keep in mind that [tex]x \ge 15[/tex] in order for the discount to kick in.
Subtracting the two amounts leads to 72x-47x = 25x. It is not a coincidence that we get a coefficient of 25 here.
Set this equal to 500 and solve for x
25x = 500
x = 500/25
x = 20
------------
If x = 20 people attend individually, then they pay 72*x = 72*20 = 1440 dollars.
If 20 people go as one group, they pay 47x = 47*20 = 940 dollars
We have a savings of 1440-940 = 500 dollars. This confirms the answer.
All 20 people must go as one group if they want to save $500.
how many number of subsets in set D
Answer: A proper subset is a subset that is not identical to the original set—it contains fewer elements. You can see that there are 16 subsets, 15 of which are proper subsets. Listing the sets is fine if you have only a few elements.
ms.smith bought a 5 pound bag of candy for her 6th grade classroom.She gave away 2 pounds of candy to her students during the first unit of instructions and ate 6 ounces of candy during planning.How many ounces of candy does Ms.Smith still have in her bag?
Answer:
42
It was on my test I put 42 a day later i checked my test the answer was correct. Sorry that I didn't really have a explanation.
But at least its correct.
Ms. Smith still have 42 ounces of candy in her bag.
What is Subtraction?To subtract means to take away from a group or a number of things.
Given that Ms. Smith bought a 5 pound bag of candy for her 6th grade classroom. She gave away 2 pounds of candy to her students during the first unit of instructions and ate 6 ounces of candy during planning.
1 pound = 16 ounces
She gave away 2 out of 5 pounds, so she is left with 5 - 2 = 3 pounds
3 pounds = 16*3 ounces = 48 ounces
She ate 6 ounces of candy
Therefore, she now has, 48 - 6 = 42 ounces of candies left with her.
Hence, Ms. Smith still have 42 ounces of candy in her bag.
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*HELP*. I need help on this stuff on I-ready... *HELP*
Answer:
First one
Step-by-step explanation:
50 + 30 can be broken up into (10x5)+(10x3). You can simplify that into 10(5+3) because 10 x 5 =50 and 10x 3 = 30. :)
Answer:
10(5+3)
Step-by-step explanation:
If If you multiply 5 and 3 by 10 you'll get 50 + 30
HELP!!!! (zoom in to see it better)
Answer:
C and D
Step-by-step explanation:
The lines are parallel to eachother dont worry about what the lines is in the middle
for the second question, it is the same thing, the lines are both going straight
which means that they are parallel
Answer:
C and D
Step-by-step explanation:
Raj and his friends went to the movies today and ate 875 Which steps can be used to find how much popcorn pieces of popcorn, or 125% more than they ate when Raj and his friends ate at the movies last week? they went to the movies last week. Check all that apply. Popcorn 125 + 750 = 875 eaten today 0 125 875 O 125 x 7 = 875 100 x 7 = 700 pieces of popcorn 100 + 750 = 850 pieces of popcorn 0 100 ? 125 + 875 = 1000 pieces of popcorn Popcorn eaten last week
Answer:
125 x 7 = 875 pieces of popcorn
100 x 7 = 700 pieces
Step-by-step explanation:
Answer:
Step-by-step explanation:
B and C
1
2
3
Use the order of operations to fin
3 x 15 + 3 x 20 - 35 = n
Thompson down the street from his home to Cameron's house. Along the way, he stopped at a bake to pick up cupcakes. if he began at (10,-9), ended at (12,-7),and stopped at the bakery at (11,-8), what are the ratios to represent his trip? Select all that apply.
1/1
2/1
1/4
1/2
PRE CALC QUESTION
For the following, find the function P defined by a polynomial of degree 3 with real coefficients that satisfy the given conditions.
The zeros are -3,-1, and 4. The leading coefficient is -5.
(type answer in standard form)
P(x)=
Answer:
-5[tex]x^{3}[/tex] + 65x + 60
Step-by-step explanation:if m 2 =6x+8 and m 6 = 8x-6, find the value of x so that l is parallel to m
Answer:
[tex]x = 7[/tex]
Step-by-step explanation:
Given
[tex]m_2 = 6x + 8[/tex]
[tex]m_6 = 8x - 6[/tex]
Required
Determine x when both lines are parallel
For parallel lines, slopes must be equal.
i.e.
[tex]m_1 = m_2[/tex]
In this case,
[tex]m_6 = m_2[/tex]
Substitute values for m6 and m2
[tex]8x - 6 = 6x + 8[/tex]
Collect Like Terms
[tex]8x - 6x = 8 + 6[/tex]
[tex]2x = 14[/tex]
Solve for x
[tex]x = 14/2[/tex]
[tex]x = 7[/tex]
Answer:7
Step-by-step explanation:
The fraction model below shows the steps that a student performed to find a quotient. Which statement best interprets the quotient? There are fraction 6 and 1 over 4 two-thirds in fraction 4 and 1 over 6.
a. There are fraction 6 and 1 over 4 five and one-sixths in fraction 2 over 3.
b. There are fraction 8 and 1 over 6 two-thirds in fraction 5 and 1 over 6.
c. There are fraction 8 and 1 over 6 five and one-sixths in fraction 2 over 3.
Answer:
C. D. E. or 3. 4. 5.
Step-by-step explanation:
A coral reef grows 0.14 m every week. How much does it grow in 14 weeks? Write your answer in millimeters.
Answer:
0.14*14= 1.96
Step-by-step explanation:
Must multiply 0.14 times 14 for the answer.
please help me with this i will mark you brainliest
Answer:
(-3,7)
Step-by-step explanation:
Hope it helps
Find A and C,Laws of sines and cosines
Answer:
[tex]AC=15.9976[/tex]
Step-by-step explanation:
Law of Sines: [tex]\frac{sin(A)}{a} =\frac{sin(B)}{b} =\frac{sin(C)}{c}[/tex]
Step 1: Define
a = 8 ft
A = 30°
b = ?
B = 89°
Step 2: Substitute and Evaluate
[tex]\frac{sin(30)}{8} =\frac{sin(89)}{b}[/tex]
[tex]bsin(30)=8sin(89)[/tex]
[tex]b=\frac{8sin(89)}{sin(30)}[/tex]
[tex]b=16cos(1)[/tex]
[tex]b=15.9976[/tex]
[tex]AC=15.9976[/tex]
which integer represents 19°F bellow
Draw out a vertical number line. Positive values are above 0, and negative values are below zero.
estimate the quotient of 9 1/3 ÷ 2 3/4
The estimated quotient is 3. This is because 9 1/3 rounds to nine and 2 3/4 rounds to 3.
Answer:
The quotient gives: 3 13/33
Step-by-step explanation:
We start by converting the mixed numbers into improper fractions, since we can easily divide fractions.
the number 9 1/3 can be written as: 27/3 + 1/3 = 28/3
the number 2 3/4 can be written as: 8/4 + 3/4 = 11/4
Now we can divide them using the properties of dividing fractions:
28/3 divided by 11/4 = 28/3 * 4/11 = 112/33
which in mixed number form is : 99/33 + 13/33 = 3 13/33
Mr. Javier purchased a number of pencils for ₱180 and sold all except 6 at a profit of ₱2 per pencil. With the total amount received, he could buy 30 more items than before. Find the number of items he bought and the cost of each in pesos
Answer:
36 pencils
[tex]Cost = 0.2[/tex]
Step-by-step explanation:
Given
Cost Price = 180
Represent the number of items by x
This implies that the cost of each item is [tex]\frac{x}{180}[/tex]
[tex]Selling\ Price = Cost + Profit[/tex]
[tex]Selling\ Price = \frac{x}{180} + 2[/tex]
Since all but 6 items were sold, the total selling price is:
[tex]Total = (x - 6)(\frac{x}{180} + 2)[/tex]
This amount can be used to buy 30 more items.
So, we have:
[tex](x - 6)(\frac{x}{180} + 2) = x + 30[/tex]
Multiply both sides by 180
[tex]180 * (x - 6)(\frac{x}{180} + 2) =180(x + 30)[/tex]
[tex](x - 6)(x + 360) = 180x + 5400[/tex]
Expand brackets
[tex]x\² + 360x - 6x - 2160 = 180x + 5400[/tex]
[tex]x\² + 354x - 2160 = 180x + 5400[/tex]
Equate to 0
[tex]x\² + 354x - 180x - 2160 - 5400 = 0[/tex]
[tex]x\² + 174x - 7560 = 0[/tex]
Expand
[tex]x\² + 210x - 36x - 7560 = 0[/tex]
[tex]x(x + 210) - 36(x + 210) = 0[/tex]
[tex](x - 36)(x + 210) = 0[/tex]
[tex]x - 36 = 0[/tex] or [tex]x + 210 = 0[/tex]
[tex]x = 36[/tex] or [tex]x = -210[/tex]
Since, number of items can't be negative, we have to discard x = -210.
Hence:
[tex]x = 36[/tex]
We can then conclude that, Mr. Javier purchased 36 pencils
Recall that
[tex]Cost = \frac{x}{180}[/tex]
[tex]Cost = \frac{36}{180}[/tex]
[tex]Cost = 0.2[/tex]
Find the value of
5x^2 if x = -3.
Step-by-step explanation:
5x²
If x = 3
Then,
5(3)²
= 5×9
= 45
Jon used 64.4 cups of flower to make 8 loaves of bread. How much flower did he use for each loaf?
Answer:
8.05 cups per loaf
Step-by-step explanation:
divide 64.4 and 8
equation
64.4÷8=8.05
10. Suppose that we have 50 balls labeled 0 through 49 in a bucket. What is the minimum number of balls that we need to draw to ensure that we get at least 3 balls which end with the same digit
Answer:
21 drawings
Step-by-step explanation:
The number labelings are 0 - 49
The minimum set that could be the same number is the labeling 0, 10 , 20
It could also be 1, 11, 21 or even 2,12,22
In all the cases, we can be sure that we might have three labelings ending with the same number when we pull our ball labeled 20
That makes a total of 21 drawings
Following are the response to the given question:
Pigeon Hole's Principle can also be used to tackle this problem. Assuming that we already have labels ranging from [tex]0\ to\ 49.[/tex]
We possess five balls which conclude with the number 0 [tex]\text{(ball \ 0, ball\ 10, ball\ 20, ball\ 30, and\ ball\ 40)}.[/tex] We possess five balls which conclude with the digit 1[tex]\bold{(ball\ 1, ball\ 11, ball\ 21, ball\ 31, ball\ 41)}.[/tex] .....I have five balls that end in the number 9 [tex]\text{(ball\ 9, ball\ 19, ball\ 29, ball\ 39, and ball\ 49)}.[/tex]Each digit ending is represented by five balls.
In the pigeonhole principle, it [tex]kn+1[/tex] objects [tex](k \geq 1)[/tex] are distributed among n boxes, one of the boxes will contain at least [tex]k+1[/tex] objects. Assume that you draw a ball and place it in a box labeled with its last digit. So there will be n = 10 boxes.
Box 0: we place balls that end in the digit 0. Box 1: we place balls that end in the digit 1. .....Box 9 is where we put balls that end in the number 9.According to the pigeon hole concept, you need to draw [tex]kn+1[/tex] balls to assure that at least one of the boxes includes [tex]k+1[/tex] objects. Because [tex]k+1 = 3,[/tex] we require three objects in at least one box (we need three balls ending with the same digit).
[tex]k + 1 = 3 \\\\k =2[/tex]
Therefore, we have to draw [tex]kn+1[/tex] balls, [tex]k = 2, n = 10[/tex], at least[tex]21\ balls[/tex] must be drawn to ensure that at least three of them have the same 1 digit.
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The GCF of 14 and a number is 7. Which of the following could be the number?
A 49
B 42
C 56
Answer:
A 49
Step-by-step explanation:
Any odd number that has 7 as a factor will be a candidate. Of the choices listed, the only possibility is ...
49
__
If the number is even and has 7 as a factor, then it will be a multiple of 14. That is, the GCF will not be 7, but will be 14. Hence, the number must be an odd multiple of 7.
Which expression is a prime polynomial, x^3-1, x^2+1, x^3+1, x^2-1
Answer:
[tex]x^2+1[/tex] cannot be factored, thus it's a prime polynomial
Step-by-step explanation:
A prime number or expression cannot be factored in any factor different from 1 and the number or expression itself.
One of the following expressions is prime. The rest of them can be factored.
[tex]x^3-1[/tex] is the difference of two cubes. It can be factored as:
[tex]x^3-1=(x-1)(x^2+x+1)[/tex]
[tex]x^3+1[/tex] is the sum of two cubes. It can be factored as:
[tex]x^3+1=(x+1)(x^2-x+1)[/tex]
[tex]x^2-1[/tex] is the difference of two squares. It can be factored as:
[tex]x^2-1=(x-1)(x+1)[/tex]
[tex]\mathbf{x^2+1}[/tex] cannot be factored, thus it's a prime polynomial
12x + 7 < -11
OR
5.2 – 8 > 40
Answer:
x < - 3/2 or x > 48/5 (option a in your list of answers)
Step-by-step explanation:
We solve for x in each inequality:
12 x + 7 < -11
subtract 7 from both sides:
12 x < - 11 - 7
12 x < -18
divide both sides by 12 to isolate "x" on the left:
x < - 18 / 12
simplify a common factor 6 in numerator and denominator on the right:
x < - 3 / 2
Now the other inequality:
5 x - 8 > 40
add 8 to both sides:
5 x > 40 + 8
5 x > 48
divide both sides by 5:
x > 48 / 5
So the answer is:
x < - 3/2 or x > 48/5
which coincides with answer a) in your list.
Please help I would appreciate
Answer:
the 1st 2nd and 5th since if there is even one negative in the fraction it makes the whole fraction negative
by which smallest number can 275 be multiplied to get perfect square