How many ways can we put 7 adults and 3 kids in line (where order matters) so that no two kids are next to each other?

Answers

Answer 1
Given that the order matters in this question, we shall apply the concept of permutation rather than computation. Thus, the number of ways in which that we can put 7 adults and 3 kids in line will be:
7P3
=210
There are more than 210 ways we can do this.

Related Questions

What is the slope of the line below

Answers

Answer: m = 2
The formula for slope can be found by finding the difference in y between two values divided by the difference in x between the same two values. In this case, you would subtract 4 from 8 and 2 from 4, to get 4/2, or 2. The slope is represented by the variable m, so m = 2.

HELP ME PLEASE!
Peter walks 30 feet away from his house and places a mirror on the ground. He backs 6 feet away from the mirror so that he can see the tip of the roof. Peter's eyes are 5 feet above the ground. Peter and the house are both perpendicular to the ground. The angles between the top of the house, the mirror, and the ground and between Peter's eyes, the mirror, and the ground are congruent as shown in the image below:
Image depicts a mirror on the ground between a person and a house. The mirror is 6 feet away from the person and 30 feet away from the house.
What is the height of the house?

Answers

By setting up a proportion based on the similar triangles formed by Peter's line of sight and the analogous line from the top of the house to the mirror, we find that the house is 25 feet tall.

According to the Law of Reflection and the information provided, we have two similar triangles: one formed by Peter's eyes, the mirror, and the point on the ground directly below his eyes, and the other formed by the top of the house, the mirror, and the point on the ground directly below the top of the house.

The first triangle has a height of 5 feet (Peter's eye level) and a base of 6 feet (the distance from Peter to the mirror). The second triangle's height is what we are trying to find (height of the house), and its base is 30 feet (distance from the house to the mirror).

Because the triangles are similar, the ratios of their corresponding sides are equal. So, we can set up the following proportion:

Height of Peter's eyes / Distance to mirror = Height of the house / Distance to mirror from house

5 feet / 6 feet = Height of the house / 30 feet

Now, cross-multiply to solve for the height of the house:

5 feet * 30 feet = Height of the house * 6 feet

Height of the house = (5 * 30) / 6

Height of the house = 150 / 6

Height of the house = 25 feet

Therefore, the height of the house is 25 feet.

The equation of the straight line of slope 3 passing through the point (2, 5) may be written as

Answers

The equation of a straight line is given by y=mx+c where m is the slope while c is the y-intercept. The formula for obtaining the slope is given by:
m=(y-y1)/(x-x1)
therefore the formula for our graph will be:
3=(y-5)/(x-2)
3(x-2)=y-5
y-5=3x-6
y=3x-6+5
y=3x-1
the answer is y=3x-1

Simplify.

Square root of 121m^8n^4

A. 11mn

B. 11m^2n^2

C. 11m^4n^2

Answers

[tex] \sqrt{121m^8n^4}= \sqrt{121} \sqrt{(m^4)^2} \sqrt{(n^2)^2}=11 m^4n^2 [/tex]

Answer:

B

Step-by-step explanation:

no

Quadrilateral ABCD is a parallelogram with diagonals that intersect at point E. If /,/, /, and /, solve for x.

A.
x = 2
B.
x = 4
C.
x = 6
D.
x = 8

Answers

It is 8 i took the final

One side of triangle is half the longest side. the third side is 7 feet less than the longest side. the perimeter is 43. find all three sides.

Answers

If x is the longest side, and y is half that length, you would have the equation

2y = x

If z is 7 less than x then that equation would look like

X = z +7

The perimeter is the sum of all the sides

P = x + y + z = 43

Now by using all three equations, we can find the value of each variable by plugging into the equations.
First, let's start by changing the first two equations to compare the values of z and y to x.

Y = x/2
Z = x - 7

Now we can use these new equations to plug into the perimeter equation and find the value of x.

43 = x + y + z Plug in your variables
43 = x + x/2 + x-7 Add 7 to both sides
50 = x + x/2 + x Multiply both sides by 2 to get rid of the fraction
100 = 2x + x + 2x Add all your x's together
100 = 5x Divide both sides by 5

X = 20

No we can use the value of x to find the values of y and z by plugging into the two equations before.

2y = 20
Y = 10

Z = 20 - 7
Z = 13

Therefore, the lengths of the sides are 20, 10, and 13

Harry Hoodeen made $24,567.00 net pay last year. His monthly expenses averaged $1,980.00. How much was left over for savings for the year?

Answers

24,567 - 12(1980)
24,567 - 23760
807

His left over savings was $807.

In which of the following quadrilaterals are consecutive angles always congruent? Check all that apply.

Answers

rectangle and square.
Consecutive angles are next to each other. squares and rectangles are the only to that has angles with the same values that are next to each other

Answer:

Rectangle and Square.  

Step-by-step explanation:

To know if the angles of a quadrilateral is congruent you must overlap these angles one over the other, if all elements of the angles coincide, the angles are congruent; if the elements do not match, the angles are not congruent. In quadrilateral rectangle and square consecutive angles are always congruent.

In other words, two or more angles are said congruent if and only if they have the same measurement.

Need help with math problem


Multiply

(3x – 7)(3x – 5)

A.
9x 2 + 6x + 35

B.
9x 2 + 36x + 35

C.
9x 2 – 36x – 35

D.
9x 2 – 36x + 35

Answers

(3x – 7)(3x – 5) term by term
1 step: 3x term 
3x*3x - 3x*5  the minus comes as you multiply by -2
2 step: -7 term
-7*3x + 7*5 the second plus comes from -*-=+

add these together
3x*3x-3x*5-7*3x+7*5 and do the multiplications: 
9x^2 -15x-21x+35=9x^2-36x+35

In 1980, the United States' national debt exceeded $9 billion dollars. Express the exact dollar amount in scientific notation.

Answers

9 billion = 9,000,000,000 = 9.0 x 10^9

Explain how you would use trig ratios to find the height of the tree if you know you are standing 30 feet from the base of the tree when you measure the 37-degree angle.

Answers

check the picture below.

make sure your calculator is in Degree mode.

From use of trigonometric ratios, it is seen that the height of the tree is; 22.61 feet

How to work with trigonometric ratios?

We are told that you are standing 30 ft from the base of a tree.

Now, the distance from where you are standing to the top of the tree will be the hypotenuse of the triangle formed by you and the tree.

Thus, if the height of the tree is h and the angle the hypotenuse makes with the 30 ft base is 37°, then we have;

h/30 = tan 37

h = = 30 * tan 37

h = 22.61 ft

Read more about Trigonometric Ratios at; https://brainly.com/question/13276558

#SPJ2

How can you tell whether a rational expression is in simplest form? Include an example with your explanation.

Answers

a rational in its most simple an be written as a fraction a/b where a and b are co-prime. Which means that there are no common factors in a and b 

for example 4/6  is not simplest form because  2 is a factor of 4 and 6
In its simplest form 4/6  is 2/3.

Rational numbers are numbers that are written as a ratio of two integers.

Let a and b be integers, hence a rational expression can be expressed as a/b

In order to tell whether a rational expression is in its simplest form, we need to ensure no integer can go in both the numerator and the denominator.

For instance, given the rational number 10/15, the simplest form of the rational number will be expressed as (5*2)/(5*3) = 2/3

learn more here: https://brainly.com/question/18736992

the sum of 3 numbers is 26. the second number is twice the first and the third number is 6 more than the second. find the number

Answers

Answer:

  the numbers are 4, 8, 14

Step-by-step explanation:

If we subtract 6 from the third number and from the total, we find that we now have 5 times the first number for a total of 20.

The first number is 4.

The second number is 2×4 = 8.

The third number is 8 + 6 = 14.

Sandy can assemble a particular type of light fixture in 3/8 hour. it takes her 2/3 hour to hang the fixture and another 1/6 hour to wire the fixture once it is hung. how many fixtures could sandy install in 29 hours?

Answers

Final answer:

Sandy can install a maximum of 24 fixtures in 29 hours.

Explanation:

To calculate the number of fixtures Sandy can install in 29 hours, we need to determine the amount of time it takes for Sandy to complete one installation process (excluding assembly time).

Sandy takes 2/3 hour to hang the fixture and another 1/6 hour to wire it, totaling

2/3 + 1/6 = 7/6 hour.

Therefore, Sandy takes 7/6 hour per fixture.

Next, we can calculate the number of fixtures by dividing the total time available (29 hours) by the time it takes for one installation process.

Number of fixtures = Total time available / Time per fixture

Number of fixtures = 29 / (7/6) = 29 * (6/7) = 174/7 = 24.86

Since we can't have a fraction of a fixture, Sandy can install a maximum of 24 fixtures in 29 hours.

Learn more about installing fixtures here:

https://brainly.com/question/24337233

#SPJ2

How do I do this someone please explain I need help

Answers

so.. she washes cars and charges 15 bucks per car...ok... Revenue( sales income), in this case is how much she gets in total income from the car washing.. .well, if she washes, say "a" automobiles, then she makes 15*a, or 15a in income, or Revenue.

now, she pays in advertising 145 bucks... and for cleaning products, she spends 3 bucks for each washed car... ok.. .so if she washes say "a" automobiles, then she spends 3*a or 3a, ok.... so, her costs for the washing cars business is 145 for ads plus 3a, or 145 + 3a is her Cost.

now, Profit is the surplus amount after you remove the cost expenses, and can only happen if the Revenue is higher or greater than the Cost.

Revenue > Cost
  15a      > 145 + 3a

when will she turn a profit?

[tex]\bf 15a \ \textgreater \ 145 + 3a\implies 15a - 3a\ \textgreater \ 145\implies 12a \ \textgreater \ 145 \\\\\\ a\ \textgreater \ \cfrac{145}{12}\implies a\ \textgreater \ 12\frac{1}{12}[/tex]

she will turn a profit after washing 12 cars and 1/12 of a car, maybe just the windshield =).... anyhow..... namely, the revenue then is greater than the cost after that, or one can say, after the 13th car washed. 

HELP might fail class

Answers

By not using the digit 0, John has 9 digits left to choose from.  By not using the letter m, John has 25 letters left to choose from.

The password pattern is <letter><letter><digit><digit><digit><digit>.  Use the Multiplication Principle:

25 x 25 x 9 x 9 x 9 x 9 = 4,100,625

Need help geometry ^^^

Answers

the term corresponding angles means that the angles are in the same relative position. if you look at A, r and w are in the same positions if we.were.to overlap the 2 intersections. So they are corresponding angles

What is i^16 simplified

Answers

[tex]\bf i^{16}\implies i^{4+4+4+4}\implies i^4\cdot i^4\cdot i^4\cdot i^4\implies 1\cdot 1\cdot 1\cdot 1[/tex]

and fairly sure you know how much that is.

WILL GIVE A BRAINLIEST PLEASE HELP!!!

Use the formula below to find the 6th term in the geometric sequence.

a(n)=(5)x(3/2)n-1

A.
5
B.
15/2
C.
1,215/32
D.
3,645/64

Answers

a(n) = a₁.(r)ⁿ⁻¹, where a₁ = 1st term, r= common ratio and n, the rank

In the formula given a₁ = 5, r = 3/2 and n = 6 (we have to find the 6th term value).

a₆ = 5.(3/2)⁶⁻¹ = 5.(3/2)⁵ = 1215/32 (answer C)

In a survey, the planning value for the population proportion is p*=.35. how large a sample should be taken to provide a 95% confidence interval with a margin of error of .05 (to the nearest whole number)?

Answers

Given:
p* = 0.35, the populatin proportion.
Sp = 0.05, the margin of error

Let n =  the size of the sample.

Because the standard error is 0.05, therefore
[tex] \sqrt{ \frac{p(1-p)}{n} } =0.05[/tex]
[tex] \sqrt{ \frac{0.35(1-0.35)}{n} } =0.05[/tex]
[tex] \frac{0.2275}{n} =0.05^{2} =0.0025[/tex]
n = 0.2275/0.0025 = 91

Answer: The sample size is 91.

The average wind speeds for one year at 44 climatic data centers around the United States are as follows:
9.0, 6.9, 9.1, 9.2, 10.2, 12.5, 12.0, 11.2, 12.9, 10.3, 10.6, 10.9, 8.7, 10.3, 10.6, 10.9, 8.7, 10.3, 11.0, 7.7, 11.4, 7.9, 9.6, 8.0, 10.7, 9.3, 7.9, 6.2, 8.3, 8.9, 9.3, 11.6, 10.6, 9.0, 8.2, 9.4, 10.6, 9.5, 6.3, 9.1, 7.9, 9.7, 8.8, 6.9, 8.7, 9.0, 8.9, 9.3

a) Make a stem plot of the average wind speeds data. The frequency in the stem for 9 to 9.9 is?

b) The first quartile for the wind speed data set is?

Answers

The stem and leaf diagram is shown below

There are a total of 48 data

Question a:
The frequency in the stem for 9 to 9.9 is 13 data

Question b:
The location of the first quartile is given by [tex] \frac{n+1}{4} [/tex], where 'n' is the number of data

We have n = 48

Location of the first quartile is at [tex] \frac{48+1}{4}= \frac{49}{4}= 12.25[/tex] rounded down to 12

The value of the lower quartile is on the [tex] 12^{th} [/tex] on the diagram which is 8.7


1. What is 3/8x < -6 or 5x>2 solved and graphed?
2. What is 2<10 -4d< 6 solved and graphed?
I appreciate your help!

Answers

The first one is a disjunction, an "or", meaning that the solution set shares no numbers on the number line.  That's how you graph these...on a number line.  Solving the first one, multiply both sides by 8 to get
[tex]3x\ \textless \ -48[/tex] and divide to get x<-16.  Now the second one, just divide both sides by 5 to get
[tex]x\ \textgreater \ \frac{2}{5} [/tex]
On a single number line, make 0 your center, put -16 where it belongs in reference to the 0 and put 2/5 where it belongs in reference to the 0. The numbers to the left of -16 are those that are less than -16, and the circle above the -16 is an open one, not including the -16.  The numbers to the right of 2/5 are those numbers that are greater than 2/5, so put an open circle above the 2/5 and go to the right with that line.  And you can see that you have a big open space between the -16 and the 2/5 where the solution set is not the same at all.  For b, solve this one simultaneously.  It is a conjunction, an "and", where there will be a solution set that is shared by both values for x.  Solve it like this...start by subtracting 10 from both sides:
-8< -4d < -4   Now, when you divide by the negative 4, you have to change the signs to greater than: 2 > d > 1.  That means, in words, that "d is less than 2 and greater than 1".  On a single number line you will have open circles above the 1 and the 2 and the numbers in between 1 and 2 are shared solutions.

Write a conditional that multiplies the value of the variable pay by one-and-a-half

Answers

A conditional is an If/Then statement. For instance, if a triangle has three equal sides, then it is equilateral. This is saying if 1.5x equals something, but you don't tell us what that something is, so can't really answer the question. Or are you supposed to make something up, for instance, if you work overtime and x represents your pay, then you will be paid 1.5x for the overtime hours. 


Find the surface area of the sphere.
Round to the nearest hundredth.

Answers

surface area is 4*pi*r^2 = 4*4*4*pi = 64pi
The answer is 50.24 (not rounded)

How much dirt is there in a hole 3 feet deep, 6 ft long and 4 ft wide?

Answers

the volume of the hole would be  3 * 6 * 4 =72 cubic feet.

 However, since it is a hole, there would be no dirt in it.

On his birthday newton was 14 years old and his father was 41 newton noticed that his age was his fathers age with the digits reversed how many years later with their ages next have their digits reversed

Answers

In 22 years, newton will be 36 and his father will be 63. The digits are reversed

When the age of Newton will be 25 years , the age of his father will be reversed i.e., 52 yrs.

It is given that when Newton was 14 years old , his fathers age was 41 yrs.

We have to find out that at what age of Newton his fathers age will be reversed again ?

Solve for the value of x ;  10 x - 14 = 12x - 28 ?

The value of x will be 7.

Let's assume the tens place as x and one's place as y.

The actual number will be ; 10 x + y.

Reverse numbers pairs can be written as (10x+y) and (10y+x).

As the age of Newton's father is 41 yrs when he is 14 yrs old , so we have ;

(10x+y) - (10y+x) = 41–14 = 27

Hence , we can say that the age difference between Newton and his father is 27 years. This age difference will be same forever.

So ;

(10x+y) - (10y+x) = 27

and we have to find all values of x and y that will satisfy this equation.

⇒ (10x+y) - (10y+x) = 27

⇒ 9x - 9y = 27

x - y = 3

For all x’s and y’s who have their difference as 3 will answer the question. For example , (4,1) (5,2) (6,3) (7,4) (8,5) …. and so on.

Since Newton's father age today is 41 yrs.

The next age to satisfy the condition is 52 yrs.

This makes Newton’s age to be 52 - 27 = 25 which is the reverse of 52.

So , the answer of the question is that Newton should be of 25yrs , for his age to be the reverse of his father’s age.

Thus , when the age of Newton will be 25 years , the age of his father will be reversed i.e., 52 yrs.

To learn more about algebra click here ;

https://brainly.com/question/25424372

#SPJ2

Directions: Describe the transformation. (x,y) -> (5x,5y)

Answers

Final answer:

The transformation (x, y) -> (5x, 5y) is a scaling transformation that dilates a point by a factor of 5 in both the x and y directions, making the entire figure five times larger while preserving its shape.

Explanation:

The transformation described by (x, y) -> (5x, 5y) is a scaling transformation or dilation in both the x and y directions by a factor of 5. What this means is that any point on the plane, when subjected to this transformation, will move five times further away from the origin along both axes. For example, if you begin with the point (1, 1), applying this transformation will result in the point (5, 5). This dilation affects all points equally, meaning that the relative distances between points are preserved, but the entire figure is made larger by a factor of 5. Therefore, if you have a figure with dimensions of length and width, after the transformation, both dimensions will be increased by five times their original measure.

Final answer:

The transformation (x, y) -> (5x, 5y) represents a dilation, enlarging a figure by a factor of 5 along both the x-axis and y-axis, which alters size but not shape.

Explanation:

The transformation described by the rule (x, y) -> (5x, 5y) is a geometric transformation known as a dilation or scaling. This type of transformation alters the size of a figure without changing its shape. Specifically, the coordinates of each point in the figure are multiplied by 5, which means that the figure is enlarged by a factor of 5 in both the x-axis (east-west direction) and the y-axis (north-south direction). If, for example, we apply this transformation to a point (1, 2), the resulting coordinates will be (5, 10), and similarly, applying it to (3, 7) would yield (15, 35). This illustrates the dependence of y on x as each x-coordinate and y-coordinate are scaled by the same factor, maintaining the shape but increasing the size.

1. Given f(x)=3x+8f(x)=3x+8 and g(x)=6x+6g(x)=6x+6 then what is (f+g)(−1))(f+g)(−1)) ?
2. Given f(x)=6x+4f(x)=6x+4 and g(x)=3x+7g(x)=3x+7 then what is (f−g)(1)) ?

Answers

f(x)=3x+8 and g(x)=6x+6 (f+g)(x) = f(x) + g(x) = (3x+8) + (6x+6) = 9x + 14 Then (f+g)(−1) = 9(-1) + 14 = 5 f(x)=6x+4 and g(x)=3x+7 (f+g)(x) = f(x) + g(x) = (6x+4) + (3x+7) = 9x + 11 Then (f−g)(1) = 9(1) + 11 = 20

What are the solutions of the equation x6 + 6x3 + 5 = 0? Use factoring to solve.

Answers

Consider the equation [tex] x^6+6x^3+5=0 [/tex].

First, you can use the substitution [tex] t=x^3 [/tex], then [tex] x^6=(x^3)^2=t^2 [/tex] and equation becomes [tex] t^2+6t+5=0 [/tex]. This equation is quadratic, so

[tex] D=6^2-4\cdot 5\cdot 1=36-20=16=4^2,\ \sqrt{D}=4,\\ \\ t_{1,2}=\dfrac{-6\pm 4}{2} =-5,-1 [/tex].

Then you can factor this equation:

[tex] (t+5)(t+1)=0 [/tex].

Use the made substitution again:

[tex] (x^3+5)(x^3+1)=0 [/tex].

You have in each brackets the expression like [tex] a^3+b^3 [/tex] that is equal to [tex] (a+b)(a^2-ab+b^2) [/tex]. Thus,

[tex] x^3+5=(x+\sqrt[3]{5})(x^2-\sqrt[3]{5}x+\sqrt[3]{25}) ,\\x^3+1=(x+1)(x^2-x+1) [/tex]

and the equation is

[tex] (x+\sqrt[3]{5})(x^2-\sqrt[3]{5}x+\sqrt[3]{25})(x+1)(x^2-x+1)=0 [/tex].

Here [tex] x_1=-\sqrt[3]{5} , x_2=-1 [/tex] and you can sheck whether quadratic trinomials have real roots:

1. [tex] D_1=(-\sqrt[3]{5}) ^2-4\cdot \sqrt[3]{25}=\sqrt[3]{25} -4\sqrt[3]{25} =-3\sqrt[3]{25} <0 [/tex].

2. [tex] D_2=(-1)^2-4\cdot 1=1-4=-3<0 [/tex].

This means that quadratic trinomials don't have real roots.

Answer: [tex] x_1=-\sqrt[3]{5} , x_2=-1 [/tex]

If you need complex roots, then

[tex] x_{3,4}=\dfrac{\sqrt[3]{5}\pm i\sqrt{3\sqrt[3]{25}}}{2} ,\\ \\x_{5,6}=\dfrac{1\pm i\sqrt{3}}{2} [/tex].

Solve the equation by graphing. If exact roots cannot be found, state the consecutive integers between which the roots are located. x2 + 4x + 3 = 0

Answers

x= -1/2 so exact should be x
Other Questions
The product of the roots of 8x - 2x = 1 is: The different degrees of sleep and wakefulness through which newborns cycle, ranging from deep sleep to great agitation, are called __________. What are the origins of the Great War? Select all that apply.1.competitiveness brought on by imperialism2.the rise in nationalism3.the build-up of arms4.the abundance of wealth5.the race for military supremacy Why did Bangladesh separate from Pakistan?A. Because the Bengali people wanted to continue to be a British colonyB. Because the Indian government restricted travel between East and West PakistanC. Because East Pakistan had greater resources than West PakistanD. Because ethnic and political differences divided East and West Pakistan what is the x-intercept of the graph of the function f(x)=x2-16x+64? Solve l=14j+3k for j. "Shakespeare's Romeo and Juliet has many themes, including the powerful nature of both love and fate. Choose one or more SECONDARY characters in the play (Tybalt, Mercutio, Nurse, Friar Lawrence, or another secondary character of your choice - NOT Romeo or Juliet) and write a 3-5 paragraph essay that discusses how this character contributes to the overall theme of the play. You may want to consider some or all of the following in your writing:- How does the secondary character you have chosen influence Romeo and/or Juliet?- How do the actions of the secondary character you have chosen impact the eventual tragic ending?- What, if anything, would have been different if this character had not been created? Would the ending be different? Why or why not?- Discuss what theme this character contributes to and how? Provide examples wherever possible." An __________ is used to indicate the repeating part of a repeating decimal. what is an equivalent ratio What is the area of the polygon given below? Why does Capulet think the following exchange is so funny?Capulet. Make haste, make haste. Sirrah, fetch drier logs:Call Peter, he will show thee where they are.Sec. Serv. I have a head, sir, that will find out logs, And never trouble Peter for the matter.He knows that Peter is not that smart.The servant is calling himself a loggerhead.Right after this exchange, the servant trips over a log.He knows that the servant has no idea where the logs are. Some teenagers seem able to skate, play basketball, or dance for hours without rest. this increased endurance is best explained by _____. In one paragraph, explain how World War I led to significant changes in society. Use specific details from the lesson and the reading to support your answer. please hurry Andrew makes $6 an hour plus $9 an hour for every hour of overtime. Overtime hours are any hours more than 40 hours for the week. Part A: Create an equation that shows the amount of wages earned, W, for working x hours in a week when there is no overtime. (3 points) Part B: Create an equation that shows the amount of wages earned, S, for working y hours of overtime. Hint: Remember to include in the equation the amount earned from working 40 hours. (3 points) Part C: Andrew earned $330 in 1 week. How many hours (regular plus overtime) did he work? Show your work. (4 points) A circle has a center of (5,-5) and goes through (6,-2). What is the radius? In some countries within the Muslim world, women have been elected to government positions, including prime minister. true or false What causes water molecules to stick together in liquid water? A.Water vapor B.Carbon dioxide C.Sun's gravity D.Hydrogen bonds Double-checking my answer.. Given 3^2x = 9^6, what value of x satisfies this equation? (Use Laws of Exponents). Thanks:) A client with gout has been advised to lose weight. she informs the nurse that she plans to go on a guaranteed rapid weight loss plan that involves fasting and heavy exercise. which response would be most appropriate? Which part of the earth is hot enough to melt rock? Steam Workshop Downloader