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3 years ago

How many 7 digit phone numbers are there assuming the first digit can't be a 0 or a 1?

1 answer:

7 0

The first digit can be any one of the numbers 2-9 That a total of 8 numbers.

The next 6 digits can be any permutation of 6 from the numbers 0 to 9.
(10 numbers)

nPr = n! / r!

so here we have 10P6 = 10! / 6! = 10*9*8*7 = 5040

So final answer is 8 * 5040 = 40,320

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PLEASE HELP ITS A TEST

xeze [42]

It is 180 because it rotates

5 0

2 years ago

Read 2 more answers

How do I round these numbers?

olga nikolaevna [1]

Do your sum which is $329.69 subtract $59.63 then if the unit is 4 or less round your answer to the nearest ten eg, 103 would be rounded to 100. If the unit is 5 and above you would round your answer up eg, 437 would be rounded to 440.

8 0

2 years ago

Write a quadratic function in standard form with a leading coefficient of 1 for the given set of zeros. 7 and 4

Viefleur [7K]

We are given : Zeros x=7 and x=4 and leading coefficent 1.

In order to find the quadratic function in standard form, we need to find the factors of quadratic function first and the multiply by given leading coefficent.

For the given zeros x=7 and x=4, we get the factors (x-7) and (x-4).

So, we need to multiply (x-7) and (x-4) by foil method.

We get

(x-7)(x-4) = x*x + x* -4 -7*x -7*-4

x^2 -4x -7x +28.

Combining like terms, we get

-4x-7x = -11x

x^2 -4x -7x +28 = x^2 -11x +28.

Now, we need to multiply x^2 -11x +28 quadratic by leading coefficent 1.

We get

1(x^2 -11x +28) = x^2 -11x +28.

Therefore, the required quadratic function in standard form is x^2 -11x +28.

6 0

3 years ago

Agent Bond is standing on a bridge, 13.5 m above the road below, and his pursuers are getting too close for comfort. He spots a

Scrat [10]

Answer:

Step-by-step explanation:

Eek! Let's give this a go. Things we know:

acceleration of Bond in free fall is -9.8 m/s/s

velocity of the truck is 25 m/s

displacement Bond will travel when he jumps is -10 m

What we are looking for is the time it will take him to hit the top of the truck, knowing that the truck can travel from one pole to the next in 1 second.

Our displacement equation is

Δx = v₀t + 1/2at²

Filling in we have

$-10=25t+\frac{1}{2}(-9.8)t^2$

Simplifying we get

$-10=25t-4.9t^2$

This is a quadratic that needs to be solved however you personally solve quadratics. When you do that, you find that the times it will take Bond to drop that displacement is either -.37 seconds or 5.47 seconds. Many things in physics can be negative, like velocity and acceleration, but time NEVER will be. So it takes Bond 5.5 seconds to drop to the roof of the moving truck. That means that he needs to jump when the truck is between the 5th and the 6th poles away from him.

Good luck with this!

Cheers!

6 0

3 years ago

There are 10 marbles in the bag below. 7 of the marbles are red, 1 is purple and 2 are green. A marble is picked at random from

zepelin [54]

Answer: a) 0.7

b) 70%

Step-by-step explanation:

a) There are 10 marbles.The red marbles are 7

so that 7/10

then change to decimal 7/10=0.7

b) if we get percentage *100

so, 7÷10*100%

70%

7 0

2 years ago