How many phone numbers without area codes are possible? the first digit cannot be zero or one.

Answers

Answer 1
Ok guys, let me explain in a way you can understand.

let’s say there’s 7 blanks :

_ _ _ _ _ _ _

the first can’t be 0 or 1 so that means that it can be 2,3,4,5,6,7,8,9 which is 8 numbers

Now we have settle what the first digit can or can’t be, there are 6 numbers left.

Because there are no more restrictions for phone numbers that don’t work (first digit can’t be one or zero was the only restriction), the question then becomes : How many 6 digit numbers are possible (000000) can count , well we know that the biggest 6 digit number is 999999 and the smallest is 000000. That means there are 999999–000000+1 numbers between them inclusive. For those of you that are curious how I got the plus one, when you are counting the amount of numbers between let’s say a and b inclusive, the amount of numbers between them inclusive is |a-b| +1. Example : The amount of numbers between 2 and 13 inclusive is just |2–13|+1 which is 12. 2,3,4,5,6,7,8,9,10,11,12,13 is 12 numbers so |a-b|+1 works for the amount of numbers between a and b inclusive.

Anyways, back to the problem. 999999–000000+1 means there are 1000000 or 1 million possible 6 digit numbers. But that’s not the answer to the problem because each 1 of those 1 million 6 digit numbers needs a 7th digit which and be any number from 2–8 . This means that you need to multiply 1000000 by 8 to get 8 million possible phone numbers. If your wondering why I multiplied by 8, let’s say the number abcdef is one of the possible 6 digit numbers. If you add a 7th digit 2–9 to our number abcdef, then our number abcdef can be 2abcdef, 3abcdef, 4abcdef, 5abcdef, 6abcdef, 7abcdef, 8abcdef, 9abcdef.

Just a quick side note for any misconceptions, when I say the number abcdef, I don’t mean a times b times c times d times e times f, I mean a is the number in the hundred thousands place, b is the number in the 10 thousands place, c is the number in the thousands place, d is the number in the hundreds place, e is the number in the tens place, f is the number in the ones place.

Back to the problem, because there are 8 possible numbers for the 7th digit (AKA the first number in the phone number) you need to multiply the 1000000 different 6 numbers by 8 because each of those numbers has 8 variations.

In summary, there are 8*1000000 or 8 million different phone numbers whose digits aren’t 0 or 1


Related Questions

PLEASE HURRY HELP!
Find the product (3a4 + 4)2

Answers

Answer:

(3a4 + 4)2

= (12a+4)2

= 24a+8

-1/3(4+z)=-5/6 I need answer ASAP

Answers

Answer:

-2/3

Step-by-step explanation:

:)

Answer:

z = - 1.5

Step-by-step explanation:

Given equation:

-1/3(4 + z) = -5/6

Multiply both sides by - 3 and simplify;

(-3)(-1/3(4 + z)) = (-3) (-5/6) 4 + z = 5/24 + z = 2.5z = 2.5 - 4z = - 1.5

How much greater is the surface area of the rectangular prism than the surface area of the cube?

A. 36 cm2
B. 33 cm2
C. 18 cm2
D. 45 cm2

Answers

Answer: 18 cm2

Step-by-step explanation: the surface area of the cube is 54 cm2 and the rectangular prism is 72 cm2 so 72 - 54 = 18

Three cubes with volumes 8 cm3, 27 cm3 and 64 cm3 are glued together to form a solid figure. What the least possible surface area (cm2) of the solid figure?

Answers

Answer:

148 cm²

Step-by-step explanation:

The cubes have sides of 2 cm, 3 cm and 4 cm respectively.

Their face area of the cubes is 4 cm², 9 cm² and 16 cm² respectively.

Total surface area of each cube is:

Side 2 cm - 6*(2*2) = 24 cm², Side 3 cm - 6*(3*3) = 54 cm², Side 4 cm - 6*(4*4) = 96 cm².

Total of three cubes:

24 + 54 + 96 = 174 cm²

When you glue the cubes together you lose an area equal to double face area of the smaller cube from the total surface area.

Possible decrease, provided full faces area covered:

2 cm cube with the other two ⇒ loss of four 2x2 faces 4*4 = 16 cm²3 cm or 4 cm cube with the other two ⇒ loss of two 3x3 and two 2x2 faces 2(9+4) = 26 cm²

The least possible surface area is:

174 - 26 = 148 cm²

☆Answer :

3Cubes :

Volume = 8cm³ ==> r = 2cmVolume = 27cm³ => r = 3cmVolume = 64cm³ => r = 4cm

Soo :

Volume - 1 = 6 × 2² = 6 × 4 = 24cm²

Volume - 2 = 6 × 3² = 6 × 9 = 54cm²

Volume - 3 = 6 × 4² = 6 × 16 = 96cm²

Totals = 24 + 54 + 96 = 174cm²

[tex] \: [/tex]

surface area = 174 - 2(3² + 2²)

surface area = 174 - 2(9 + 4)

surface area = 174 - 2(13)

surface area = 174 - 26

serface area = 148cm²

[tex] \: [/tex]

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Need Kona talaga para bukas please

Answers

Answer:8

Step-by-step explanation:

Find the slope and y intercept of the line 3x+2y=-6

Answers

Answer:

Step-by-step explanation:

Slope -  -3/2

y-intercept- (0,-3)

if 8 ^ x=2 sqrt 2 find the value of x.

Answers

Answer:

[tex]{ \rm{ {8}^{x} = \sqrt{2} }} \\ \\ { \rm{ {2}^{3x} = {2}^{ \frac{1}{2} } }} \\ \\ { \rm{3x = \frac{1}{2} }} \\ \\ { \rm{x = \frac{1}{6} }}[/tex]

wHaT iS tHe AnWsEr?????????????
2,000 +300000000000000000000000000000000000

Answers

Answer:

3.0 E35

Step-by-step explanation:

Thanks.

Which of the following functions has an inverse that is NOT a function?

A) f(x) = (1/2)x - 1/2
B) f(x) = (x - 1)^3 + 2
C) f(x) = 2^x
D) f(x) = x(x - 1)

Answers

Step-by-step explanation:

Content

Functions and their inverses

We begin with a simple example.

Example

Let f(x)=2x and g(x)=x2.

Apply the function g to the number 3, and then apply f to the result:

g(3)=32andf(32)=3.

A similar thing happens if we first apply f and then apply g:

f(3)=6andg(6)=3.

It is clear that this will happen with any starting number. This is expressed as

f(g(x))g(f(x))=x,for all x=x,for all x.

The function f reverses the effect of g, and the function g reverses the effect of f. We say that f and g are inverses of each other.

As another example, we have

(x−−√3)3=xandx3−−√3=x,

for all real x. So the functions f(x)=x3 and g(x)=x−−√3 are inverses of each other.

If x≥0, then (x−−√)2=x and x2−−√=x. If x<0, then x−−√ is not defined. So the functions f(x)=x2 and g(x)=x−−√ are inverses of each other, but we need to be careful about domains. We will look at this more carefully later in this section.

Basics

In an earlier section of this module, we defined the composite of two functions h and g by (g∘h)(x)=g(h(x)).

Definitions

The zero function 0–:R→R is defined by 0–(x)=0, for all x.

The identity function id:R→R is defined by id(x)=x, for all x.

Example

Consider a function f:R→R.

Prove that

0–∘f=0–

f∘id=f

id∘f=f.

Show that f∘0– does not necessarily equal 0–.

Solution

We have (0–∘f)(x)=0–(f(x))=0, for all x, and so 0–∘f=0–.

We have (f∘id)(x)=f(id(x))=f(x), for all x, and so f∘id=f.

We have (id∘f)(x)=id(f(x))=f(x), for all x, and so id∘f=f.

Consider the function given by f(x)=2, for all x. Then f∘0–(x)=f(0–(x))=f(0)=2, and so f∘0–≠0–.

Definition

Let f be a function with both domain and range all real numbers. Then the function g is the inverse of f if

f(g(x))g(f(x))=x,for all x,and=x,for all x.

That is, f∘g=id and g∘f=id.

Notes.

Clearly, if g is the inverse of f, then f is the inverse of g.

We denote the inverse of f by f−1. We read f−1 as 'f inverse'. Note that f inverse has nothing to do with the function 1f.

Example

Let f(x)=x+2 and let g(x)=x−2. Show that f and g are inverses of each other.

Solution

We have

f(g(x))=f(x−2)=x−2+2=x,for all x(f∘g=id)

and

g(f(x))=g(x+2)=x+2−2=x,for all x(g∘f=id).

Hence, the functions f and g are inverses of each other.

Exercise 5

Find the inverse of

f(x)=x+7

f(x)=4x+5.

Example

Let f(x)=ax+b with a≠0. Find the inverse of f.

Solution

We have x=f(x)−ba, for all x. So let g(x)=x−ba. Then

f(g(x))g(f(x))=f(x−ba)=a(x−ba)+b=x=g(ax+b)=(ax+b)−ba=x,

for all x. Hence, g is the inverse of f.

Exercise 6

Show that f(x)=x5 and g(x)=x15 are inverses of each other.

Find the inverse of f(x)=x3+2.

We do not yet have a general enough concept of inverses, since x2 and x−−√ do not fit into this framework, nor do ex and logex. We will give a definition that covers these functions later in this section.

The horizontal-line test

Consider the function f(x)=x2, which has domain the reals and range A={x:x≥0}. Does f have an inverse?

The following graph shows that it does not. We have f(−2)=f(2)=4, and so f−1(4) would have to take two values, −2 and 2! Hence, f does not have an inverse.

Graph of y = x squared and the line y = 4 on the one set of axes.

This idea can be formulated as a test.

Horizontal-line test

Let f be a function. If there is a horizontal line y=c that meets the graph y=f(x) at more than one point, then f does not have an inverse.

Notes. Remember that the vertical-line test determines whether a relation is a function.

Example

Consider the function

f(x)=x3−x=(x+1)x(x−1).

Its graph is shown in the following diagram.

Graph of y = x cubed minus x.

Does f have an inverse?

Solution

The line y=0 meets the graph at three points. By the horizontal-line test, the function f does not have an inverse.

The function whose inverse does not exist is f(x) = x(x - 1)

The correct option is (D)  f(x) = x(x - 1)

What is inverse of a function?

An inverse is a function that serves to “undo” another function. That is, if f(x) produces y, then putting y into the inverse of f produces the output x.

First,  f(x)= [tex]\frac{1}{2} x -\frac{1}{2}[/tex]

let y= [tex]\frac{1}{2} x -\frac{1}{2}[/tex]

On solving for x we get a unique value

Then replace x and y.

It shows that the function have a unique value, which satisfies the condition of inverse.

Now, f(x) =[tex](x - 1)^3 + 2[/tex]

Again, solving for y we can get a cube root function which is a inverse of cube.

Hence, the inverse of [tex](x - 1)^3 + 2[/tex] exists.

Next, f(x) =[tex]2^x[/tex]

Solving for above we get logarithmic value. Log function are inverse of exponential function.

Hence, the inverse of [tex]2^x[/tex] exists.

Last, f(x)= x(x-1)

Solving for above create a square value.

The inverse of square never exist because having square root gives two value one is positive and other is negative.

Hence, the inverse of x(x-1) not exists.

Hence the function whose inverse does not exist is x(x-1).

Learn more about inverse of function here:

https://brainly.com/question/2541698

#SPJ2


The container that holds the water for the football team is
1/2
full. After pouring in 9 gallons of water, it is 4/5 full. How many gallons can the container hold?

Answers

Answer:

45

Step-by-step explanation:

nnnnnnnnnnbbbbbbbhhhhbjjjj

Plz help I need help plz

Answers

It’s the third answer

The perimeter of a rectangular garden is 332 m.
If the length of the garden is 93 m, what is its width?

Answers

Answer:

73

Step-by-step explanation:

332÷2= 166

166 - 93 = 73

The population of Westport was 43,000 at the beginning of 1980 and has steadily decreased by 1% per
year since.
Find the population at the beginning of 1994. Round to the nearest person.

Answers

Answer:

37356

Step-by-step explanation:

Greatest common factor of 30 and 75

Answers

Step-by-step explanation:

The prime numbers 5 and 3 are both factors that are common to 30 and 75. The product of these factors is 3×5 = 15. Thus, the “Greatest Common Factor” of 30 and 75 is 15.

Answer:

the Greatest common factor of 30 and 75 is 15

Step-by-step explanation:

The product of these factors is 3×5 = 15. Thus, the “Greatest Common Factor” of 30 and 75 is 15.

Solve for x.



5x−2(x+1)=1/4 ​



Enter your answer as a fraction in simplest form in the box.

x =

Answers

Answer:

x=3/4

Step-by-step explanation:

Answer:

X= 3/4

Step-by-step explanation:

Distribute

Combine like terms

Add 2 to both sides of the equation

Simplify

Divide both side s of the equation by the same turm

Simplify

Consider the following two loans for P=$12,000.

Loan A: 5 year loan, annual interest rate of 5%.
Loan B: 3 year loan, annual interest rate of 8%.

Answers

Answer:

Simple interest-?

Step-by-step explanation:

P= 12000

T=5yrs

R=5%

Now,

Simple interest - PTR/100

= 12000*5*5/100

= $3000

Again,

P=12000

T=3yrs

R=8%

Now,

Simple interest - PTR/100

= 12000*3*8/100

= $2880

Hope this helps.

whats is the value of X

need help asap

Answers

Answer:

8

Step-by-step explanation:

Answer:

x= 98

First, you have to find what the third angle is so;

180-53-45=82

The third angle in 82.  

A straight line is 180º. So you need to subtract 180-82 to get 98.

Step-by-step explanation:

Use logarithms to solve the equation for t. (Round your answer to two decimal places.)
2000/(1 + 6e−0.7t) = 1000

Answers

9514 1404 393

Answer:

  2.56

Step-by-step explanation:

Multiply by (1+6e^(-.7t))/1000:

  2000/1000 = 1 +6e^(-0.07t)

  1 = 6e^(-0.07t) . . . . . . . . . subtract 1

  e^(0.07t) = 6 . . . . . . . . . . multiply by e^(0.07t)

  0.07t = ln(6) . . . . . . . . . take the natural log

  t = ln(6)/0.07 . . . . . . . divide by the coefficient of t

  t ≈ 2.55966 ≈ 2.56

If f(x) is a linear function, what is the value of n?
Х
-4
f(x)
1-25
-10
-1
n
20
2
4
9

Answers

Answer:

The value of n is 5.

Step-by-step explanation:

We have been given that f(x) is a linear function and we are asked to find the value of n from the provided table.

x            f(x)

-4          -25

-1            -10

n             20

First of all we will find the slope of the given using our given points (-4,-25) and (-1,-10) in slope formula.

m = y2-y1/x2-x1

Upon substituting coordinates of our given points we will get,

m = -10--25/-1--4

m = -10+25/-1+4

m = 15/3

m = 5

Since we know that the equation of a line in slope-intercept form is:

y = mx + b,where, m= Slope and b= y-intercept.

Upon substituting m = 5 in slope-intercept form of equation we will get,

y = 5x + b

Now let us find y-intercept by substituting coordinates of one point in our given line.

-10 = 5(-1) + b

-10 = -5 + b

-10 + 5 = -5 + 5 + b

-5 = b

y = 5x - 5

Now let us find value of n by substituting x = n and y = 20 in our equation.

20 = 5 * n - 5

20 + 5 = 5 * n - 5 + 5

25 = 5 * n

25/5 = 5 * n/5

5 = n

Therefore, the value of n is 5.

given the drawing below what is the difference between angle D and angle B​

Answers

Answer:

given the drawing below what is the difference between angle D and angle B​

Step-by-step explanation:

anyone have the answer?

Answers

Answer:

50.3 (rounded) I think? Could be wrong, however, it's what I got

कौन-सा शब्द यौगिक है।

क. पुस्तकालय। ख. भाई की बहन। ग लंकेश​

Answers

Answer:

help please............

Iihhhhhb. Yes I did but it wasn’t bad enough for you guys too have too many people too and I’m tired too

how to multiply 21 x 25 in oldschool way

Answers

use a calculator i don't know

How many 0.25 are there in 10.5?​

Answers

10.5/0.25 = 42

the answer is 42

Answer:

42

Step-by-step explanation:

to find how many 0.25 there are in 10.5 we have to divide 10.5 by 0.25

10.5÷0.25

=42

Hope this helped you- have a good day bro cya)

Mae receives $79.00 for working one 10-hour day. One day she had to stop after working 7 hours because of a doctor’s appointment. How much did she make that day? I need help

Answers

1. First we divide $79.00 by 10 hours to see how much Mae gets payed each hour.
79.00 divided by 10 = $7.90/hr

2. Multiply $7.9 by 7 hours = $55.30

Answer:

Mae got payed $55.30 for working a 7 hour day

Which number is not in scientific notation? (5 points)

11 ⋅ 1021
5.7 ⋅ 109
3.1 ⋅ 10−12
1.67 ⋅ 10−5

Answers

9514 1404 393

Answer:

  (a) 11·10^21

Step-by-step explanation:

"Scientific notation" has a mantissa that has one digit to the left of the decimal point. The number 11·10^21 has two digits to the left of the decimal point, so is not in the form required by scientific notation.

  11·10^21 is not in scientific notation

_____

It would be correctly written in scientific notation as as 1.1·10^22.

Answer:

A) 11 ⋅ 10^21

In the diagram, lines BC and DE are parallel.
What is the measure of Zx?

Answers

180-42-109=29
Thats all
Make me the bairnlieat

hey guys pls help me i need to submit this before 1hr .graphing an inverse function.y = 4x + 12 using the x values (-2,-1, 0, 1 and 2).​

Answers

Answer:

4, 8, 12, 16, 24

Step-by-step explanation:

Replace the x with the x values starting at -2 and use the equation with the new x value.

E.g.

x = -2

y = 4 * -2 + 12

y = 4

Sorry if my explanation isn't the best.

Last year, the Galaxy Fair Amusement Park installed a family roller coaster they named The Twist. This coaster was designed to accommodate riders from age 4 to adult and features a tall climb hill and several banking turns. Overall, the park has been disappointed in the reception of The Twist, and very few families are riding the coaster this season. After some research, they discovered that park guests think the climb hill is too tall and fast for younger riders. Galaxy Fair Amusement Park has asked a roller coaster design firm to help them redesign The Twist during the coming off season. The quadratic function that represents the current climb hill is () = −0.102 + 3.6 − 2.4 and the quadratic function that represents the proposed redesign of the climb hill is () = −0.032 + 1.62 − 6.87. In these functions, the value of x represents the time, in seconds, since the roller coaster train cars have left the station, and the output variable is the height of the roller coaster track, in feet, above the ground. 1. Rewrite both () and () from standard form into vertex form. Explain your process. HINT: Each function has a common factor. Start by dividing it out. 2. State the vertex of each function. What does each vertex represent in context of The Twist? 3. Compare the a-value of () to the a-value of the parent quadratic function. What effect does this value have on a parabola? 4. Sketch both of the functions () and () on a single xy-plane. Describe the steps you took to create your sketch. 5. Use the vertex forms of () and () and the sketch you created in question 4 to describe the track changes that occur when the function that represents the climb hill is altered from () to (). Do you think these changes will help younger riders better enjoy The Twist? Explain.

Answers

Omg no lol a las autoridades del estado y a la prensa local el pasado domingo por el grupo a las autoridades del departamento del interior del estado en el estado del país en la capital mexicana y que se encuentra a un lado del país y a las autoridades del estado a las que no se ha podido hacer el

Answer:

can you add a picture or summerize this

Step-by-step explanation:

******Please help me help please help me ******

Answers

9514 1404 393

Answer:

  y = 8

Step-by-step explanation:

If the variation is direct, any multiplier of the x-value will also multiply the y-value.

  old value × -1 = new value

  x: 4 × -1 = -4

  y: -8 × -1 = 8

The new value of y is 8.

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8 + (-7) - (7) = 8 + 7 + (-4) Here is a linear equation in two variables: 2x+4y31=123 Which action would most likely cause the Equal Employment OpportunityCommission to intervene?A. A corporation decides to gear its next advertising campaignspecifically toward white men.B. A researcher publishes a study claiming men are betteremployees than women.C. A federal agency has mostly white agents even though it providesservices primarily to minorities.D. A company fires an employee after finding out that she was notborn in the United States. What is the nutrient indicator of Amino Acids? A large percentage of the students (is, are)staying home from school today. In 1999 the army of country Z started to collect data from all their recruits. As part of the process, they conducted a full physical examination in which audition was measured and reported as normal hearing, low hearing loss, and severe hearing loss. Unfortunately, 5 years later country Z went into a war with country Y. In 2018 a researcher from University U decided to conduct a study in which she investigated the association between hearing loss and suffering a war injury. What type of study design is being illustrated in this example In your opinion, what is one of the most significant inventionsever created? 1Mr. Johnson wants to fill up his car's gas tank. The car has a 25 gallon gas tank and there are 4 gallons of gas already in the tank. Gas costs $3.04 for each gallon. Mr. Johnson has $50 to spend on gas. Will he have enough money. Show your work and justify your answer. 3x - 5y = 4, -2x + 6y = 18 (system of equations) Which are descriptions of early cities?Check all that are true.People developed written language and recorded their history.People established laws.People lived together.People had specialized jobs.People worked together to obtain food. When does it have kinetic energy what is the answer to 8 + k -3 Please help me !!!!!! What is the relationship between the radius of a circle and its diameter?Question 2 options: please answer the question aboveit's (Septagon) A group of 15 people dines at your restaurant, and their total bill is $315. They decide to split the bill evenly between each person, and each person presents a coupon for $5 off their meal. How much does each diner pay?? $16 $21 $26 $48 $54 on the map above, which one of the following boxes is in an area where the population density is high and the level of economic development is low? pure water has a pH of_ a. 6 b. 7 c. 8 d. 9 What can you conclude from the fact that peoplewith anorexia often suffer from hair loss and weakenedimmune systems?a. Thinness is a leading cause of baldnessb. Anorexia attacks white blood cellsc. Our bodies can't function properly without foodd. Men develop anorexia more often than women optimistic people view challenges as opportunities to influence decisions.