Answer: 1/30 is the probability.
a boat travels upstream for 96 miles in 4 hours and returns in 3 hours traveling downstream in a local stream of water. what is the rate of the boat in still water and the rate of the current?
The rate of the boat in still water is 27.428571428571427 miles per hour and the rate of the current is 3.4285714285714284 miles per hour.
Let's call the rate of the boat in still water "r" and the rate of the current "c". Then the rate of the boat traveling upstream is "r - c" and the rate of the boat traveling downstream is "r + c".
We can use the following formula to calculate the rate of the boat in still water: r = (distance traveled upstream + distance traveled downstream) / (total time taken)
distance traveled upstream = 96 miles
distance traveled downstream = 96 miles
total time taken = 4 hours + 3 hours = 7 hours
r = (96 + 96) / 7 = 192 / 7 = 27.428571428571427 miles per hour
Next, we can use the formula for the rate of the boat traveling upstream to calculate the rate of the current:
96 = (r - c) * 4
96 = 4r - 4c
4c = 4r - 96
c = r - 24
Substituting the value of r that we found earlier, we get:
c = 27.428571428571427 - 24 = 3.4285714285714284 miles per hour
Therefore, the rate of the boat in still water is 27.428571428571427 miles per hour and the rate of the current is 3.4285714285714284 miles per hour.
To learn more about upstream-downstream,
Visit; brainly.com/question/13461234
#SPJ4
The rate of the boat in still water is 27.428571428571427 miles per hour and the rate of the current is 3.4285714285714284 miles per hour.
Let's call the rate of the boat in still water "r" and the rate of the current "c". Then the rate of the boat traveling upstream is "r - c" and the rate of the boat traveling downstream is "r + c".
We can use the following formula to calculate the rate of the boat in still water: r = (distance traveled upstream + distance traveled downstream) / (total time taken)
distance traveled upstream = 96 miles
distance traveled downstream = 96 miles
total time taken = 4 hours + 3 hours = 7 hours
r = (96 + 96) / 7 = 192 / 7 = 27.428571428571427 miles per hour
Next, we can use the formula for the rate of the boat traveling upstream to calculate the rate of the current:
96 = (r - c) * 4
96 = 4r - 4c
4c = 4r - 96
c = r - 24
Substituting the value of r that we found earlier, we get:
c = 27.428571428571427 - 24 = 3.4285714285714284 miles per hour
Therefore, the rate of the boat in still water is 27.428571428571427 miles per hour and the rate of the current is 3.4285714285714284 miles per hour.
To learn more about upstream-downstream,
brainly.com/question/13461234
#SPJ4
find the direction of the force on side 1, that runs from (0,l) to (l,l)
The direction of the force on side 1 is 45° downwards from the positive x-axis. The direction of the force is the opposite of the angle obtained in step 3, which is 45° downwards from the positive x-axis.
1. Draw a right triangle, with the two points of the side as the vertices.
2. Using the Pythagorean theorem, calculate the length of the side.
3. Use the inverse tangent function to calculate the angle between the two points.
4. The direction of the force is the opposite of the angle obtained in step 3, which is 45° downwards from the positive x-axis.
Learn more about angle here
https://brainly.com/question/28451077
#SPJ4
Please help in number 10
Answer:80%
Step-by-step explanation:
1/5 = 20%
100-20=80
Complete the transformations below.
Then enter the final coordinates of the figure.
The value of the coordinates of the figure after transformation is: A'' = (-3, 3), B'' = (9, 3), and C'' = (9, 12).
What is transformation?The transformation, or f: X X, is the name given to a function, f, that maps to itself. After the transformation, the pre-image X becomes the picture X. Any operation, or a combination of operations, such as translation, rotation, reflection, and dilation, can be used in this transformation. A function can be moved in one way or another using translation, rotation, reflection, and dilation. A function can also be scaled using rotation around a point. Two-dimensional mathematical figures move about a coordinate plane according to transformations.
From the given figure, the coordinates of A, B, and C are:
A = (-3, -1)
B = (1, -1)
C = (1, 2)
Applying the transformation of <2, 1> to the coordinates, we add 2 to x value and 1 to the y value:
A' = (-3, -1) = (-1, 1)
B' = (1, -1) = (3, 1)
C' = (1, 2) = (3, 4)
Applying the transformation dilate k =2, we multiply the new coordinates with 3:
A'' = (-3, -1) = (-1, 1) = (-3, 3)
B'' = (1, -1) = (3, 1) = (9, 3)
C'' = (1, 2) = (3, 4) = (9, 12)
Hence, the value of the coordinates of the figure after transformation is:
A'' = (-3, 3)
B'' = (9, 3)
C'' = (9, 12)
Learn more about transformation here:
https://brainly.com/question/29194193
#SPJ1
Answer:
A(-3,0) B(9,9) C(9,0)
Step-by-step explanation:
I had the question before
Proposed solutions for which any denominator equals ____ are excluded from the solution set of a rational equation.
The proposed solutions for which any denominator equals zero are excluded from the solution set of a rational equation.
To solve a rational equation, multiply each side by the equation's terms' least common denominator (L C D), then solve the resultant equation. Because a rational expression does not exist when its denominator is 0, suggested solutions with any denominator equal to 0 are eliminated from the solution set.
Extraneous solutions in rational equations are numbers that make any denominator in the original problem to be 0. Of course, when we have 0 in the denominator, we get an undefined expression. As a result, we would have to exclude any numbers that would result in the denominator being 0.
For more questions on Proposed solutions of rational equation
https://brainly.com/question/4985720
#SPJ4
inductive logic depends on the truth of the premises in order for the conclusion to be true. true false
The argument is deductive if the arguer thinks that the truth of the premises unquestionably establishes the validity of the conclusion.
The argument is inductive if the arguer thinks that the truth of the premises offers only solid grounds for thinking the conclusion is probably true.
An argument from a particular example to a general rule is known as induction. Deduction leads to a valid conclusion, whereas inductive reasoning merely leads to a likely result based on experience. This is how induction differs from the deduction.
Know more about argument
https://brainly.com/question/3775579
#SPJ4
How do you solve the equation 2x+3y=6?
Which ordered pairs are solutions to the equation 2x+3y=6?
The ordered pairs that are solutions to the equation 2x + 3y = 6 include the following:
Ordered pair (0, 2).Ordered pair (3, 0).What is an ordered pair?In Mathematics, an ordered pair can be defined as a pair of two elements or data points that are commonly written in a fixed order within parentheses as (x, y), which represents the x-coordinate and the y-coordinate on the coordinate plane of any graph.
How to find an ordered pair that is a solution to the equation?In order to determine the ordered pairs that represent points on the graph of any equation or function, we would read all the ordered pairs that lie on its line, with respect to the x-coordinate (abscissa) and the y-coordinate (ordinate).
By critically observing the graph of the given equation 2x + 3y = 6, the required solutions include following;
Ordered pair = (0, 2).Ordered pair = (3, 0).Read more on ordered pair here: brainly.com/question/25462418
#SPJ1
1. A car uses 40 litres of petrol to drive 500 km. Calculate the rate of petrol consumption in km per litre.
The rate of petrol consumption in km per llitre given the distance covered and the capacity of Petrol used is 12.5 km per liter
What is the rate of petrol consumption in km per llitr?Total distance covered by the car = 500 km
Total capacity of Petrol used = 40 litres
The rate of petrol consumption in km per llitre = Total distance covered by the car / Total capacity of Petrol used
= 500 km / 40 liters
= 12.5 km per liter
Therefore, the unit rate of Petrol consumption of the car is 12.5 km per liter
Read more on unit rate:
https://brainly.com/question/19493296
#SPJ1
1/4 x 5 help pls its for my sis and im really busy
Answer:
1.25 as decimal
5/4 as fraction
1 1/4 as mixed number
Step-by-step explanation:
Hope it helps! =D
how many primitive roots does 42 have
The number 42 has 4 primitive roots.
Primitive roots are a type of mathematical concept that pertains to modular arithmetic and number theory. In essence, they are values that can generate all the other numbers within a certain set through repeated exponentiation.
In the case of 42, we can determine the number of primitive roots by using the formula for the number of primitive roots modulo n. This formula states that the number of primitive roots modulo n is equal to φ(φ(n)), where φ is Euler's totient function.
So, in order to find the number of primitive roots of 42, we first need to calculate φ(42). Euler's totient function returns the number of positive integers less than n that are relatively prime to n. Since 42 is an even number, it can be easily determined that
=> φ(42) = φ(2 * 3 * 7)
=> (1 - 1/2) * (1 - 1/3) * (1 - 1/7) * 42 = 12.
Next, we need to find φ(12). Since 12 is an even number, its totient function can also be calculated easily, yielding
=> φ(12) = φ(2^2 * 3)
=> (1 - 1/2) * (1 - 1/3) * 4 = 4.
Finally, using the formula mentioned earlier, we can calculate the number of primitive roots of 42 as
=> φ(φ(42)) = φ(12) = 4.
So, to summarize, 42 has 4 primitive roots.
To know more about Primitive roots here.
https://brainly.com/question/30049990
#SPJ4
Question 2 15n + 2 Let {an} be a sequence such that sn = 3n - 9 Compute ) an. k=1 If this is divergent, input "0" as your answer If applicable, submit answers as a decimal (up to 4 digits)
The value is -6
We are given a sequence {an} such that sn = 3n - 9. We can find an by using the formula sn = an + d(n - 1).
Substituting the values for sn and d (which is 1 in this case), we get
an = 3n - 9 - (n - 1)
an = 2n - 10
Therefore, when k = 1, an = 2(1) - 10 = -6.
The answer value is -6.
Expand it to 2 liens
The answer is -6, which can be obtained by using the formula an = 3n - 9 - (n - 1).
Learn more about value here
https://brainly.com/question/18523098
#SPJ4
please help me!!! kinda lost
B. The value of a is negative, so the vertex is a minimum.
About VertexVertex is the math word for angle. Most geometric shapes, whether two or three dimensional, have vertices. For example, a square has four vertices, which are its four corners. Vertex can also refer to a point in an angle or in a graphical representation of an equation.
When two lines meet at a point, they form an angle. For polygons, the angle included at each vertex is the interior angle of the polygon.
A vertex is also sometimes used to indicate the 'top' or high point of something, such as the vertex of an isosceles triangle, which is the 'upper' angle across from its base, but this is not its strict mathematical definition.
Learn more about vertex at https://brainly.com/question/12563262
#SPJ1
is (x-3) a factor of 2x^(3)-11x^(2)+12x+9
Answer:
Step-by-step explanation:
x
=
−
1
2
,
3
Decimal Form:
x
=
−
0.5
,
3
How to Identify the Constant of Proportionality
When two variables are proportional to one another either directly or indirectly, their connection can be expressed as y is kx or y is k/x
What does a proportionality constant example look like?To indicate the amount of money you must pay at the gas station, for instance, we may write y = kx, where x = the amount of gas in gallons, y = the price in dollars, and k is a proportionality constant. To put it another way, the cost you pay is directly correlated with the number of gallons pumped.When two variables are proportional to one another either directly or indirectly, their connection can be expressed as y = kx or y = k/x, where k specifies how the two variables are connected to one another. This k is referred to as the proportionality constant.To learn more about Proportional refer to:
https://brainly.com/question/27598477
#SPJ4
Multi-Step Equation!!
Can someone please explain how to get this step by step?
The answer of given question is fraction 3/5.
In math, what is a fraction?An element of a whole is a fraction. The number is represented mathematically as a quotient, where the numerator and denominator are split. Both are integers in a simple fraction. A fraction appears in the numerator or denominator of a complex fraction. The numerator of a proper fraction is less than the denominator.
What three types of fractions are there?There are three main categories of fractions in mathematics. Proper fractions, incorrect fractions, and mixed fractions are these three types. The expressions with a numerator and a denominator are called fractions. We categorise its types based on these two terms.
[tex]\frac{5}{3}a+\frac{4}{5}=a+\frac{7}{5}\\\\\frac{5}{3}a-a=\frac{7}{5}-\frac{4}{5}\\\\ \frac{2}{3}a=\frac{3}{5}\\\\=\frac{9}{15} =\frac{3}{5}[/tex]
To know more about fraction visit:-
brainly.com/question/17724027
#SPJ1
mr crates, the principal at a local middle school, made a rule that there must be 1 adult for every 4 students attending a feild trip.
The number of adults for 24 students is 6.
What is an equation?In mathematics, an equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign =.
Given that, Mr.Cates, the principal at a local middle school, made a rule that there must be 1 adult for every 4 students attending a field trip.
Let the number of students be y and the number of adults be x.
Now, the equation is y=4x
If y=12
Then, x=3
If y=24
Then, x=6
If y=40
Then, x=10
Therefore, the number of adults for 24 students is 6.
To learn more about an equation visit:
https://brainly.com/question/14686792.
#SPJ1
"Your question is incomplete, probably the complete question/missing part is:"
Mr.Cates, the principal at a local middle school, made a rule that there must be 1 adult for every 4 students attending a field trip
Complete the table to show the number of adults for 12, 24 and 40 students.
Number of Students Number of Adults
12 _____
24 _____
40 _____
Question: 1-14
2020-2021 T-Math-Alg1-T7-CBT: Section 1 - No Calculator
the value of a certain car after yeørs is modeled by the expression 15. 000(0. 77. What are the initial cost, I, and the rate of depreciation, r, of this car
The initial cost of the car is 15,000 and the rate of depreciation is 0.77.
The initial cost, I, of the car is 15,000 and the rate of depreciation, r, is 0.77. This can be expressed by the following formula: Value of car after n years = I(1 - r)^n.
We can calculate the rate of depreciation and the initial cost by rearranging the formula:
r = 1 - (Value of car after n years/I)^(1/n)
I = Value of car after n years/(1 - r)^n
In our case, the value of the car after years is 15,000(0.77) = 11,550. Therefore, we can calculate the initial cost and rate of depreciation as follows:
r = [tex]1 - (11,550/I)^(1/n) = 1 - (11,550/15,000)^(1/n) = 0.77[/tex]
I =[tex]11,550/(1 - 0.77)^n = 15,000[/tex]
Therefore, the initial cost of the car is 15,000 and the rate of depreciation is 0.77.
Learn more about rate of depreciation here:
https://brainly.com/question/11861805
#SPJ4
Solve the following exponential equation. Express the solution set in terms of natural logarithms or common logarithms. Then, use a calculator to obtain a decimal approximation for the solution.
Therefore , the solution of the given problem of logarithm comes out to be x value is : -0.5215.
Exactly what is a logarithm?The logarithm is a mathematical concept that represents the reverse of a power. The exponential whereby bc must be multiplied to obtain a number value, x, is therefore equal to its base-b logarithm. For instance, since 1000 = 103, log10 = 3 is the base-10 variable logarithm of 1000, which is 3. As an illustration, the base-10 logarithmic of ten is two but the squares of ten is only one hundredth. Log 100 = 2. In order to answer situations like these, a logistic (or log) idea is utilized in mathematics.
Here,
Given :
Expression of e is
=> e¹⁻⁴ˣ = 1219
Applying log both side
=> log e¹⁻⁴ˣ = log1219
=> (1-4x) loge = log1219
=> 1-4x = 3.086
=> 1 -3.086 = 4x
=-> -2.086 = 4x
=> x = -2.086/4
=> x = -0.5215
Therefore , the solution of the given problem of logarithm comes out to be x value is : -0.5215.
To know more about logarithm visit:
https://brainly.com/question/30085872
#SPJ1
If angle b i two more than three time angle c, angle b and c are complimentary what i the meaure of each angle
The measure of each angles are one is 28 and other is 68.
If angle b is two more than three times angle c, then we can write the equation:
b = 3c + 2
Since angle b and angle c are complementary, their sum is equal to 90 degrees:
b + c = 90
We can substitute the value of b from the first equation into the second equation:
3c + 2 + c = 90
4c + 2 = 90
4c = 88
c = 22
So, angle c is 22 degrees and angle b is equal to 3c + 2 = 3 * 22 + 2 = 68 degrees.
To learn more about substitution
https://brainly.com/question/572814
#SPJ4
how many subsets does [n] have that contain exactly one of the elements 1 and 2?
The number of subsets that [n] have which contain exactly one element 1 and 2 is 2⁽ⁿ⁻¹⁾ .
Let us assume that [n] means the set {1, 2, 3, ..., n}.
Now For a subset having n elements ,we have = 2ⁿ total subsets, including the empty set and the set itself.
If we are looking for subsets that contain exactly one of the elements 1 and 2, there are two possibilities:
⇒ The subset contains element 1 but not element 2,
⇒ The subset contains element 2 but not element 1.
If we remove 1 and 2 from this , then the set [n] contains (n-2) elements,
So , the number of subsets become = 2⁽ⁿ⁻²⁾ subsets.
So , there is two ways to have exactly one of elements 1 or 2: add {1} to the subsets described, or add the subset {2} to subsets just described.
Therefore , [n] will contain 2⁽ⁿ⁻²⁾ subsets exactly one of 1 or 2
Learn more about Subsets here
https://brainly.com/question/17514113
#SPJ4
Philip's granola directions call for 3 ounces of nuts to every 4 ounces of raisins. He uses 2 ounces of nuts to every 3 ounces of raisins. Is Philip using the correct ratio of nuts to raisins?
Philip is not using the correct ratio of nuts to raisins
How to determine the true statementThe directions call for a ratio of 3 ounces of nuts to every 4 ounces of raisins (3/4),
and Philip is using a ratio of 2 ounces of nuts to every 3 ounces of raisins (2/3).
3/4 and 2/3 are not equivalent values
These ratios are different, so Philip is not using the correct ratio of nuts to raisins as specified in the directions.
Read more about equivalent ratio at
https://brainly.com/question/2328454
#SPJ1
Which ordered pairs represent points on the
graph of this equation? Select all that apply.
6
y = -x
5
(-5, -6)
(3,-5)
(6,4)
(-3, 7)
(5,-2)
(-6, 3)
The ordered pair that represents points om thr given equation is;
Option A: (-5, -6)
How to Identify the Ordered Pairs?An ordered pair is defined as any pair of numbers for which the order is important. Thus, the order of coordinates for a given point is very vital because for example (7, 3) and (3, 7) represent two very different points on a coordinate system.
The equation is; y = ⁶/₅x
1) At x = -5, we have;
y = ⁶/₅(-5)
y = -6
2) At x = 3, we have;
y = ⁶/₅(3)
y = 18/5
y = 3.2
3) At x = 6, we have;
y = ⁶/₅(6)
y = 7.2
4) At x = -3, we have;
y = ⁶/₅(-3)
y = -3.2
5) At x = 5, we have;
y = ⁶/₅(5)
y = 6
Thus, only option A corresponds to the correct ordered pair.
Read more about Ordered Pairs at; https://brainly.com/question/1528681
#SPJ1
Which given value, if any, is a solution of the equation a + 16 = −30 for a: {–46, –14, 14, 36}?
Answer: 14
Step-by-step explanation:
first Time taking account class and I have no idea please help I dont know how to do any of these
The final balance of all transaction is $45,880 both in Total Assets and Total Liabilities and Equities.
Please refer to the attached table below for the completed and balanced table.
We will discuss how each transaction is recorded:
a. When Pamela deposit $42,000 to the business bank, it will be recorded as cash inflow and her capital.
b. The purchase of office supplies will be recorded on account. Then, the supplies will record $2,080 and the same account will be recorded under accounts payable.
c. Record cash inflow of $5,760 and the same amount under fees earned.
d. Paid rent by cash will decrease the amount of cash by $2,550 and the same amount is recorded under Rent Expense account.
e. Cash outflow by $940 and decrease on the accounts payable account by the same amount.
f. Records accounts receivable of $4,720 and fees earned with the same amount.
g. Records cash outflow by $850. Records $570 under automobile expense and $280 for Miscellaneous expense.
h. Cash outflows by $1,790 and salaries expense by the same amount.
i. The amount of supplies decreases by $850 and records under the account of supplies expense by the same amount.
j. Cash outflow by $1,700 and records under Drawings account for the same amount.
Please note that all expenses should be recorded as a negative value.
Finally, we can check and confirm that our records are balance by comparing the total Assets and Total liabililties and Equity we have. The total assets is $45,880 and so the Total Liabilities and Equity.
Learn more about Assets and Liabilities here: brainly.com/question/13731427
#SPJ1
3. An artist is selling children's crafts. Necklace cost $2.25 each, and bracelets cost $1.50 per each. Select all the combinations of necklaces and bracelets that the artist could sell for exactly $12.00.
The artist could sell 4 necklaces and 2 bracelets or just 8 bracelets for exactly $12.
What is an equation?An equation is an expression that uses mathematical operations to show the relationship between numbers and variables. Types of equations are linear, quadratic, cubic and so on.
Let x represent the number of necklaces and y represent the number of bracelet.
Necklace cost $2.25 each, and bracelets cost $1.50 per each. The artist could sell exactly $12.00. Hence:
2.25x + 1.5y = 12
From the graph, the points (4,2) and (0, 8) satisfy this equation
Find out more on equation at: https://brainly.com/question/2972832
#SPJ1
Over a 1. 35-hour period of time, a family walk 0. 75 km, stop to talk to the neighbor, and then walk another 1. 15 km before reaching their destination. What is the average speed of the family during their walk?
The average speed of the family during their walk over a time period of 1.35 hours is 1.407 km/hr
Let us say that the distance covered by the family is x
so , according to the formula of average speed
Average speed = total distance covered/total time taken
Hence,
average speed = [tex]\frac{0.75+1.15}{1.35} km/hr[/tex]
= [tex]\frac{1.9}{1.35} km/hr[/tex]
= 1.407 km/hr
therefore, the average speed of the family is 1.407 km/hr
Learn more about average speed here:
https://brainly.com/question/11306709
#SPJ4
This is a acute-angled triangle
true/false
if false make correct shape of acute-angled triangle
Pls help
the state of oregon has an entire are of 9.0 x 10
The state of Oregon has an area of 90,000 square kilometers.
1. Take the given area of 9.0 x 10^6 square kilometers
2. Move the decimal point 6 places to the left
3. The new area is now 90,000 square kilometers
The state of Oregon has an area of 90,000 square kilometers, which is equal to 9.0 x 10^6 square kilometers.
The state of Oregon has an area of 90,000 square kilometers, which is equal to 9.0 x 10^6 (nine million) square kilometers. This is an area of around 553,000 square miles, and is roughly equivalent to the size of the United Kingdom. It is the 9th largest state in the United States, and is bordered by the states of Washington, Idaho, California, Nevada, and the Pacific Ocean. It is home to many different types of ecosystems, from coastal rainforests to high desert areas
The complete question is :
The state of Oregon has an area of 90,000 square kilometers, which is equal to 9.0 x 10^6 square kilometers.
learn more about area here
https://brainly.com/question/27683633
#SPJ4
300×165 express your answer using the correct number of significant figures.
Answer:
50,000
Step-by-step explanation:
300×165=49,500
approximately 50,000
The answer of the expression using the correct number of significant figures is 300 × 165 = 49500 = 5000, and the significant figure is 1.
What is significant figure?The crucial or important digits that accurately represent the meaning of a certain number are known as the significant figures of that number. 6.658, for instance, has four significant digits. These huge amounts give the numbers accuracy. Additionally, they are known as significant digits.
The given expression is 300 × 165.
To find the answer with the correct number of significant figure multiply the two terms:
300 × 165 = 49500
Round the answer to the closest whole number:
49500 = 5000
Now, strip the trailing 0's in the answer.
The number of significant digit in 5000 is 1.
Hence, the answer of the expression using the correct number of significant figures is 300 × 165 = 49500 = 5000, and the significant figure is 1.
Learn more about significant figures here:
https://brainly.com/question/29153641
#SPJ4
Write the equation for the hyperbola with foci (1, -5) (9, -5) and conjugate axis of length 6.
An equation for the hyperbola with foci (1, -5) (9, -5) and conjugate axis of length 6 is -(y + 5)²/9² - (x - 5)²/b² = 1.
How to determine the equation of the hyperbola?Mathematically, the standard form of the equation of a hyperbola is represented by this mathematical expression:
(y - k)²/a² - (x - h)²/b² = 1
Where:
a represents the semi-major axis.b represents the semi-minor axis.h and k represents the center.y and x represents the point.From the information provided above, we have the following parameters about the equation of this hyperbola:
Center (h, k) = (5, -5).
Also, the vertices is given by:
2c = -5 - (-5)
2c = -5 + 5
c = 0
Since the conjugate axis has a length of 6, we have:
2b = 6
b = 6/2
b = 3
Therefore, the value of a is given by:
c² = a² + b²
a² = c² - b²
a² = 0² - 3²
a = 0 - 9
a = -9.
So, the equation of this hyperbola is as follows;
-(y + 5)²/9² - (x - 5)²/b² = 1
Read more on hyperbola here: brainly.com/question/27928401
#SPJ1