Answer:
a. 5×=8+2
5×=10
b. 4×-2×=9+3
2×=13
c. 6×-2×=8-3
4×=5
Please answer this question now in two minutes
Answer:
m∠C = 102°
Step-by-step explanation:
This diagram is a Quadrilateral inscribed in a circle
The first step is to determine what m∠B
is
The sum of opposite angles in an inscribed quadrilateral is equal to 180°
m∠D + m∠B = 180°
m∠B = 180° - m∠D
m∠B = 180° - 80°
m∠B = 100°
Second step is we proceed to determine the exterior angles of the circle
m∠ADC = 2 × m∠B
m∠ADC = 2 × 100°
m∠ADC = 200°
m∠ADC = m∠CD + m∠AD
m∠AD = m∠ADC - m∠CD
m∠AD = 200° - 116°
m∠AD = 84°
The third step is to determine m∠BAD
m∠BAD = m∠AD + m∠AB
m∠BAD = 84° + 120°
m∠BAD = 204°
The final step Is to determine what m∠C is
It is important to note that:
m∠BAD is Opposite m∠C
Hence
m∠C = 1/2 × m∠BAD
m∠C = 1/2 × 204
m∠C = 102°
Solve. 4x−y−2z=−8 −2x+4z=−4 x+2y=6 Enter your answer, in the form (x,y,z), in the boxes in simplest terms. x= y= z=
Answer:
(-2, 4, 2)
Where x = -2, y = 4, and z = 2.
Step-by-step explanation:
We are given the system of three equations:
[tex]\displaystyle \left\{ \begin{array}{l} 4x -y -2z = -8 \\ -2x + 4z = -4 \\ x + 2y = 6 \end{array}[/tex]
And we want to find the value of each variable.
Note that both the second and third equations have an x.
Therefore, we can isolate the variables for the second and third equation and then substitute them into the first equation to make the first equation all one variable.
Solve the second equation for z:
[tex]\displaystyle \begin{aligned} -2x+4z&=-4 \\ x - 2 &= 2z \\ z&= \frac{x-2}{2}\end{aligned}[/tex]
Likewise, solve the third equation for y:
[tex]\displaystyle \begin{aligned} x+2y &= 6\\ 2y &= 6-x \\ y &= \frac{6-x}{2} \end{aligned}[/tex]
Substitute the above equations into the first:
[tex]\displaystyle 4x - \left(\frac{6-x}{2}\right) - 2\left(\frac{x-2}{2}\right)=-8[/tex]
And solve for x:
[tex]\displaystyle \begin{aligned} 4x+\left(\frac{x-6}{2}\right)+(2-x) &= -8 \\ \\ 8x +(x-6) +(4-2x) &= -16 \\ \\ 7x-2 &= -16 \\ \\ 7x &= -14 \\ \\ x &= -2\end{aligned}[/tex]
Hence, x = -2.
Find z and y using their respective equations:
Second equation:
[tex]\displaystyle \begin{aligned} z&=\frac{x-2}{2} \\ &= \frac{(-2)-2}{2} \\ &= \frac{-4}{2} \\ &= -2\end{aligned}[/tex]
Third equation:
[tex]\displaystyle \begin{aligned} y &= \frac{6-x}{2}\\ &= \frac{6-(-2)}{2}\\ &= \frac{8}{2}\\ &=4\end{aligned}[/tex]
In conclusion, the solution is (-2, 4, -2)
Answer:
x = -2
y =4
z=-2
Step-by-step explanation:
4x−y−2z=−8
−2x+4z=−4
x+2y=6
Solve the second equation for x
x = 6 -2y
Substitute into the first two equations
4x−y−2z=−8
4(6-2y) -y -2 = 8
24 -8y-y -2z = 8
-9y -2z = -32
−2(6-2y)+4z=−4
-12 +4y +4z = -4
4y+4z = 8
Divide by 4
y+z = 2
z =2-y
Substitute this into -9y -2z = -32
-9y -2(2-y) = -32
-9y -4 +2y = -32
-7y -4 = -32
-7y =-28
y =4
Now find z
z = 2-y
z = 2-4
z = -2
Now find x
x = 6 -2y
x = 6 -2(4)
x =6-8
x = -2
A bag contains twelve marbles, which includes seven red marbles and five blue marbles. Roja reaches into the bag and pulls out four marbles. a) How many different sets of four marbles can be pulled from this bag? b) How many of these sets contain two red marbles and two blue marbles? c) How many of these sets contain all red marbles? d) How many of these sets contain all red marbles or all blue marbles?
Answer:
a) 495
b) 210
c) 35
d) 40
Step-by-step explanation:
Given a total of 12 marbles.
n = 12
Number of red marbles = 7
Number of blue marbles = 5
a) Number of different sets of 4 marbles that can be made from this bag ?
This is a simple combination problem.
where n = 12 and r = 4.
So, answer will be:
[tex]_{12}C_4[/tex]
Formula:
[tex]_{n}C_r = \dfrac{n!}{(n-r)!r!}[/tex]
[tex]_{12}C_4 = \dfrac{12!}{(8)!4!} = \dfrac{12\times 11\times 10\times 9}{4 \times 3\times 2} =\bold{495}[/tex]
b) Two red and two blue marbles:
The answer will be:
[tex]_{7}C_2 \times _{5}C_2 = \dfrac{7\times 6}{2} \times \dfrac{5\times 4}{2} =\bold{210}[/tex]
c) all red marbles.(4 chosen out of 7 red and 0 chosen out of 5 blue marbles)
[tex]_{7}C_4 \times _{5}C_0 = \dfrac{7\times 6\times 5\times 4}{4\times 3\times 2} =\bold{35}[/tex]
d) all red or all blue.(all red marbles plus all blue marbles)
All red marbles:
[tex]_{7}C_4 \times _{5}C_0 = \dfrac{7\times 6\times 5\times 4}{4\times 3\times 2} \times 1=\bold{35}[/tex]
All blue marbles:
[tex]_{7}C_0 \times _{5}C_4 = 1 \times \dfrac{5\times 4\times 3\times 2}{4\times 3\times 2} =\bold{5}[/tex]
So, answer is 40.
70000000000x50000000000000
Answer:
Step-by-step explanation: Multiply
70000000000*50000000000000=3.5e+24
The graph of f(x) = StartRoot x EndRoot is reflected over the y-axis. Use the graphing calculator to graph this reflection. Which list contains three points that lie on the graph of the reflection? (–81, 9), (–36, 6), (–1, 1) (1, –1), (16, –4), (36, –6) (–49, 7), (–18, 9), (–1, 1) (1, –1), (4, –16), (5, –25)
Answer:
(–81, 9), (–36, 6), (–1, 1) are the correct three points.
Step-by-step explanation:
Given the function:
[tex]f(x) =\sqrt x[/tex]
Please refer to the attached image.
The green line shows the graph of actual function.
It is reflected over y axis.
The reflected graph is shown in black color in attached image.
When reflected over y axis, the sign of variable [tex]x[/tex] changes from Positive to Negative.
So, the resultant function becomes:
[tex]f(x)=\sqrt{-x}[/tex]
i.e. we will have to give the values of x as negative now.
so, the options in which value of x is negative are the possible answers only.
The possible answers are:
(–81, 9), (–36, 6), (–1, 1) and
(–49, 7), (–18, 9), (–1, 1)
Now, we will check the square root function condition.
In the 2nd option, (–18, 9) does not satisfy the condition.
So, the correct answer is:
(–81, 9), (–36, 6), (–1, 1)
Answer:
A on E2020
Step-by-step explanation:
:)
If sin Θ = 5 over 6, what are the values of cos Θ and tan Θ?
Answer:
Check explanation
Step-by-step explanation:
Sin∅=5/6
Opp=5. Hyp=6
Adj= (√6²+5²)
= √11
Cos∅=(√11)/6
Tan∅=5/(√11)
PLEASE HELP, WILL GIVE BRAINLIEST IF CORRECT!!!! (08.06 MC) Mike and his friends bought cheese wafers for $2 per packet and chocolate wafers for $1 per packet at a carnival. They spent a total of $25 to buy a total of 20 packets of wafers of the two varieties. Part A: Write a system of equations that can be solved to find the number of packets of cheese wafers and the number of packets of chocolate wafers that Mike and his friends bought at the carnival. Define the variables used in the equations. (5 points) Part B: How many packets of chocolate wafers and cheese wafers did they buy? Explain how you got the answer and why you selected a particular method to get the answer. (5 points)
Answer:
x = 5 , y = 15
Step-by-step explanation:
You can solve this using substitution.
Let the quantity of cheese wafers be denoted by x and the quantity of chocolate wafers denoted by y
2x + 1y = 25
x + y = 20
These two equations are the answer to part A, (remember to include the above prompt which says what x and y denote).
For part B I used substitution because it was more applicable to the question then addition or elimination.
ACTUAL WORK
Set 2x + 1y = 25 equal to x
x = 25 - y / 2
Replace x with y in the second equation
(25 - y / 2) + y = 20
And solve for y
y = 15
Since we know what y is we can replace y in the second equation and find what x is
x + 15 = 20
Solve for x
x = 5
Answer:
5 Cheese Wafers and 15 Chocolate Wafers
Step-by-step explanation:
solve this equation -2x+9=-5x-15
Answer:
x = -8
I hope this helps!
need help will give 5 stars.
Answer:
t=0.64
Step-by-step explanation:
h = -16t^2 +4t +4
We want h =0 since it is hitting the ground
0 = -16t^2 +4t +4
Using the quadratic formula
a = -16 b = 4 c=4
-b ± sqrt( b^2 -4ac)
----------------------------
2a
-4 ± sqrt( 4^2 -4(-16)4)
----------------------------
2(-16)
-4 ± sqrt( 16+ 256)
----------------------------
-32
-4 ± sqrt( 272)
----------------------------
-32
-4 ± sqrt( 16*17)
----------------------------
-32
-4 ± sqrt( 16) sqrt(17)
----------------------------
-32
-4 ± 4 sqrt(17)
----------------------------
-32
Divide by -4
1 ± sqrt(17)
----------------------------
8
To the nearest hundredth
t=-0.39
t=0.64
Since time cannot be negative
t=0.64
Answer:
0.64
Step-by-step explanation:
0 = -16t^2 + 4t + 4
-4(4t^2 - t -1) = 0
t = [-(-1) +/- sqrt (1 - 4*4*-1)] / 8)
t = 0.64, -0.39
answer is 0.64
If 4SINB=3SIN(2A+B) :
Prove that:7COT(A+B)=COTA
Answer:
Step-by-step explanation:
Given the expression 4sinB = 3sin(2A+B), we are to show that the expression 7cot(A+B) = cotA
Starting with the expression
4sinB= 3sin(2A+B)
Let us re write angle B = (A + B) - A
and 2A + B = (A + B) + A
Substituting the derived expression back into the original expression ww will have;
4Sin{(A + B) - A } = 3Sin{(A + B)+ A}
From trigonometry identity;
Sin(D+E) = SinDcosE + CosDSinE
Sin(D-E) = SinDcosE - CosDSinE
Applying this in the expression above;
4{Sin(A+B)CosA - Cos(A+B)SinA} = 3{Sin(A+B)CosA + Cos(A+B)sinA}
Open the bracket
4Sin(A+B)CosA - 4Cos(A+B)SinA = 3Sin(A+B)CosA + 3Cos(A+B)sinA
Collecting like terms
4Sin(A+B)CosA - 3Sin(A+B)cosA = 3Cos(A+B)sinA + 4Cos(A+B)sinA
Sin(A+B)CosA = 7Cos(A+B)sinA
Divide both sides by sinA
Sin(A+B)CosA/sinA= 7Cos(A+B)sinA/sinA
Since cosA/sinA = cotA, the expression becomes;
Sin(A+B)cotA = 7Cos(A+B)
Finally, divide both sides of the resulting equation by sin(A+B)
Sin(A+B)cotA/sin(A+B) = 7Cos(A+B)/sin(A+B)
CotA = 7cot(A+B) Proved!
Tim has an after-school delivery service that he
provides for several small retailers in town. He
uses his bicycle and charges $1.25 for a delivery
made within 1 mi, $1.70 for a delivery of at
least 1 mi but less than 1 mi, $2.15 for a
delivery of at least 1. mi but less than 2 miles,
and so on. If Tim raised his rates by 10%, what
would he be paid to deliver a package 35
miles?
Answer:
Step-by-step explanation:
tim has an after school delivery service that he provides for several small retailers in town. he uses his bicycle and charges $1.25 for a delivery made within 1 1/2 miles, $1.70 for a delivery of at least 1 1/2 miles but less than 1 3/4 miles. $2.15 for a delivery of at least 1 3/4 miles but less than 2 miles, and so on. if tim raised his rates by 10%, what would he be paid to deliver a package 3 1/8 miles.
Answer:
From the question asked the cost of additional 1/4 mile (1 3/4 - 1 1/2) is $0.45 ($1.7 - $1.25). If the rate is increased by 10% (0.1), the new price for an additional 1/4 mile would be 1.1 (1 + 0.1) × 0.45 = $0.495.
Tim new charge rate are as follows:
$1.25 for a delivery made within 1 1/2 miles
$1.745 for a delivery of at least 1 1/2 miles but less than 1 3/4
$2.24 or a delivery of at least 1 3/4 miles but less than 2
$2.735 or a delivery of at least 2 miles but less than 2 1/4
$3.23 or a delivery of at least 2 1/4 miles but less than 2 1/2
$3.725 or a delivery of at least 2 1/2 miles but less than 2 3/4
$4.22 or a delivery of at least 2 3/4 miles but less than 3
$4.715 or a delivery of at least 3 miles but less than 3 1/4
Since 3 1/8 is within 3 miles and 3 1/4 miles, Tim would charge $4.715 to deliver a package 3 1/8 miles.
determine the image of the point p[-3,10) under the translation [5,-7]
[tex](-3+5,10-7)=(2,3)[/tex]
what is the answer to 1/8=s-3/4
Answer:
7/8 =s
Step-by-step explanation:
1/8=s-3/4
Add 3/4
1/8 + 3/4 = s -3/4 +3/4
1/8 + 3/4 = s
Get a common denominator
1/8 + 3/4 *2/2 = s
1/8 + 6/8 =s
7/8 =s
1/8 = s - 3/4
1/8 = s -6/8 ( * 2/2)
7/8 = s
s = 7/8
Evaluate the following expression. −8 × (−10) −7× 1/−1
Answer:
87Step-by-step explanation:
[tex]-8\left(-10\right)-7 \times \frac{1}{-1}=87\\\\\mathrm{Apply\:rule}\:-\left(-a\right)=a\\\\=8\times \:10-7\times \frac{1}{-1}\\\\8\times \:10=80\\\\7\times \frac{1}{-1}=-7\\\\=80-\left(-7\right)\\\\\mathrm{Apply\:rule}\:-\left(-a\right)=a\\\\=80+7\\\\=87[/tex]
4x=24 solve equation
Answer:
x=6
Step-by-step explanation:
Rearrange:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
4*x-(24)=0
Step by step solution :
STEP
1
:
Pulling out like terms
1.1 Pull out like factors :
4x - 24 = 4 • (x - 6)
Equation at the end of step
1
:
STEP
2
:
Equations which are never true
2.1 Solve : 4 = 0
This equation has no solution.
A a non-zero constant never equals zero.
Solving a Single Variable Equation:
2.2 Solve : x-6 = 0
Add 6 to both sides of the equation :
x = 6
One solution was found :
x = 6
Answer:
x= 24/ 4
Step-by-step explanation:
You can simplify it
x= 6/1 which is x= 6
please can someone help me solve this.. please help!!
Step-by-step explanation:
Hello,
Firstly just look to triangle BDE,
Here, you will find that,
140° = y+80° {the exterior and opposite interior angle of a triangle is equal}.
or, y= 140°-80° {shifting 80° to another side and subtracting it.}
Therefore, the value of y is 60°.
now, let's simply work with line EB or EG. we get;
angle GEF + y=180° { being a linear pair}.
or, angle GEF + 60°= 180°
or, angle GEF = 180°-60°
Therefore, the value of angle GEF = 120°.
now, looking in triangle EFG, we get;
angle GEF + 35°+x= 180° { the sum of interior angle of a triangle is 180°}.
or, 120°+35°+ x= 180°
or, x= 180°- 155°
Therefore, the value of x is 25°.
now, lastly finding the value of "z"
We find that x= z {being vertical opposite angle}
or, z =25°
Therefore, the value of z is 25°.
So, the values are,
x=25°
y=60°
and z= 25°
Hope it helps...
A holiday company charters an aircraft to fly to Malta at
a cost of $22 000. It then sells 150 seats at $185 each and a
futher 35 seats at a 20% discount. Calculate the profit made
per seat if the plane has 200 seats.
Answer:
$54.65 profit per seat
Step-by-step explanation:
150(185) + 35(185)(.8) = 27,750 + 5,180 = 32,930 - 22,000 = 10,930
10,930/200 = $54.65 profit per seat
Answer:
$54.65
Step-by-step explanation:
First, we find the total amount made. This is easy:
(150 x 185) + (35 x .8(185)) =
27750 + 5180 =
32930
We then subtract the $22000, so the company makes a profit of 10930. There are 200 seats, so the profit made per seat is $54.65
Solve for x in the equation x squared + 11 x + StartFraction 121 Over 4 EndFraction = StartFraction 125 Over 4 EndFraction.
Answer:
Below
Step-by-step explanation:
● x^2 + 11x + 121/4 = 125/4
Substract 125/4 from both sides:
● x^2 + 11x + 121/4-125/4= 125/4 -125/4
● x^2 + 11x - (-4/4) = 0
● x^2 +11x -(-1) = 0
● x^2 + 11 x + 1 = 0
This is a quadratic equation so we will use the determinanant (b^2-4ac)
● a = 1
● b = 11
● c = 1
● b^2-4ac = 11^2-4*1*1 = 117
So this equation has two solutions:
● x = (-b -/+ √(b^2-4ac) ) / 2a
● x = (-11 -/+ √(117) ) / 2
● x = (-11 -/+ 3√(13))/ 2
● x = -0.91 or x = -10.9
Round to the nearest unit
● x = -1 or x = -11
The solutions are { -1,-11}
The solution of the equation x² + 11x + (121/4) = 125/4 will be 0.09 and negative 11.09.
What is the solution to the equation?The distribution of weights to the variables involved that establishes the equilibrium in the calculation is referred to as a result.
The equation is given below.
x² + 11x + (121/4) = 125/4
Simplify the equation, then the equation will be
4x² + 44x + 121 = 125
4x² + 44x + 121 - 125 = 0
4x² + 44x - 4 = 0
x² + 11x - 1 = 0
We know that the formula, then we have
[tex]\rm x = \dfrac{-b \pm \sqrt {b^2 - 4ac}}{2a}[/tex]
The value of a = 1, b = 11, and c = -1. Then we have
[tex]\rm x = \dfrac{-11 \pm \sqrt {11^2 - 4 \times 1 \times (-1)}}{2 \times 1}\\\rm x = \dfrac{-11 \pm \sqrt {121 +4}}{2 }\\x = \dfrac{-11 \pm \sqrt {125}}{2 }[/tex]
Simplify the equation, then we have
x = (- 11 ± 11.18) / 2
x = (-11 - 11.18) / 2, (-11 + 11.18) / 2
x = -11.09, 0.09
The solution of the equation will be 0.09 and negative 11.09.
More about the solution of the equation link is given below.
https://brainly.com/question/545403
#SPJ6
How can you change a rational number to a decimal? Can you give an exsample?
Answer:
1/2=0.5
Step-by-step explanation:
¼=0.25
¾=0.75
Need help please asap this is not asap but please still give an answer im stuck
Answer:
135 cubes
Step-by-step explanation:
First, find the volume of the box with the equation V = Bh, where B is the area of the base and h is the height.
V = (2.25)(0.75)(1.25)
V = 2.109375
Next, find the volume of one cube with the side length 1/4 with V = Bh:
V = (0.25)(0.25)(0.25)
V = 0.015625
Then, divide the volume of the box by the volume of one cube:
2.109375 / 0.015625
= 135
Jenny had a wardrobe full of 35 different shirts. In order to make more space in her closet, she got rid of 9 of them. What is a reasonable
estimate for the percentage of shirts Jenny got rid of?
There is no one set answer because there are many ways to estimate here.
35 rounds to 40
9 rounds to 10
She got rid of 10 shirts out of 40, so 10/40 = 1/4 = 0.25 = 25% is the estimated percentage of shirts she got rid of. This is one possible estimate.
Using a calculator, the actual percentage is 9/35 = 0.2571 = 25.71% approximately. So our estimate isn't too bad. Our estimate is an underestimate.
Evaluate the function below at x=5. Then, enter your solution. f(x)=3(2)^x
Answer:
Solution: f(5) = 96
Step-by-step explanation:
f(5) = 3(2)^5
f(5) = 3 (2 × 2 × 2 × 2 × 2)
f(5) = 3 (32)
f(5) = 96
simpily 2^3×3^2=6^5
Answer:
2^3×3^2=6^5 equation is wrong because
2×2×2×3×3=72
6^5=6×6×6×6×6=36×36×6=7776
the two numbers are not equal
Mate, I think your question is wrong ! ;(
[tex]Corrected \\ Question...\\[/tex] (2^3)^2*(3^2)^3=6^5
Can someone help me with this please it’s algebra 2
Answer:
7 8 9
Step-by-step explanation:
I need help factoring this question, Factor 4(20) + 84.
Answer:
164
Step-by-step explanation:
B for brackets
O for of
D for division
M for multiplication
A for addition
S for subtraction
You first start with the brackets (20) and multiply with 4 which is equal to 80 and then add it to 84 which makes 164
I hope this helps
The height of a building model is 2% of its actual height. If the building
model is 3 feet tall, how tall is the actual building?
Answer:
x = 150 feets
Step-by-step explanation:
Given that,
The height of a building model is 2% of its actual height.
The building model is 3 feet tall, h = 3 feet
We need to find the height of the actual building. Let it is x.
According to question,
h = 2% of x
We have, h = 3 feet
So,
[tex]x=\dfrac{h}{2\%}\\\\x=\dfrac{3}{2/100}\\\\x=150\ \text{feet}[/tex]
So, the actual height of the building is 150 feets.
A rectangular prism has a volume of 864 cubic units. How many cubic unit will fill the volume of the solid if they were packed without any gaps or overlaps
Answer: 864.
Step-by-step explanation:
The volume of a rectangular prism has a volume equal to:
V = W*L*H
W = width
L = length
H = height
We know that the volume is equal to 864 cubic units.
This means that if we want to fill the prism such that there is no gap or overlap, we should use exactly 864 unit cubes.
Reduce any fractions to lowest terms. Don't round your answer, and don't use mixed fractions. 4x+4\leq9x+84x+4≤9x+8
Answer:
x ≥ -4/5
Step-by-step explanation:
Maybe you want to solve ...
4x+4 ≤ 9x +8
0 ≤ 5x +4 . . . . . subtract 4x+4
0 ≤ x +4/5 . . . . . divide by 5
-4/5 ≤ x . . . . . . . subtract 4/5
Answer:
x ≥−4/5
Step-by-step explanation:
True or false? If false give counterexample The product of a rational number and an integer is not an integer
Answer:
False
Step-by-step explanation:
Required
State if the product of rational numbers and integer is an integer
The statement is false and the proof is as follows
Literally, rational numbers are decimal numbers that can be represented as a fraction of two integers;
Take for instance: 0.2, 0.5, 2.25, etc.
When any of these numbers is multiplied by an integer, the resulting number can take any of two forms;
1. It can result to an integer:
For instance;
[tex]0.2 * 5 = 1[/tex]
[tex]0.5 * 4 = 2[/tex]
[tex]2.25 * 8 = 18[/tex]
2. It can result in a decimal number
For instance;
[tex]0.2 * 3 = 0.6[/tex]
[tex]0.5 * 5 = 2.5[/tex]
[tex]2.25 * 7 = 15.75[/tex]
From (1) above, we understand that the product can result in an integer.
Hence, the statement is false
A combination lock uses three numbers between 1 and 46 with repetition, and they must be selected in the correct sequence. Is the name of "combination lock" appropriate? Why or why not? Choose the correct answer below. A. No, because the multiplication counting rule would be used to determine the total number of combinations. B. Yes, because the combinations rule would be used to determine the total number of combinations. C. No, because factorials would be used to determine the total number of combinations. D. No, because the permutations rule would be used to determine the total number of combinations.
The correct answer is D. No because the permutations rule would be used to determine the total number of combinations.
Explanation:
The difference between a combination and a permutation is that in permutations the order is considered. This applies to the numbers in a lock because these need to be in order. Therefore, to analyze the permutations in a lock, the rule for permutations should be used. This includes the general formula P (n,r) =[tex]\frac{n!}{(n-r) !}[/tex]; in this, n is the number of objects and r refers to the objects used in a permutation. Thus, the term "combination" is inappropriate because this is a permutation, and the permutation rule should be used.