1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nalin [4]
3 years ago
11

How many 7-digit phone numbers are possible, assuming that the first digit can’t be a 0 or a 1? (b) re-solve (a), except now ass

ume also that the phone number is not allowed to start with 911?
Mathematics
1 answer:
sladkih [1.3K]3 years ago
3 0
A. We are going to form 7 digit numbers from the set {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

where the first digit cannot be 0 or 1.

so we have 8 choices for the 1. digit, and 10 choices for all the other 6 digits.

this means there are 8*10*10*10*10*10*10=8* 10^{6} possible numbers.

b.

consider the numbers which start with 911. There are 10*10*10*10=10 ^{4} such numbers, since for the 4th, 5th, 6th and 7th digits we have 10 choices.

then we remove this number, from the one we found in a:

There are in total 8* 10^{6}-10^{4}=7,990,000 numbers which don't start with 911.


Answer:

a.8*10^{6}
b.7,990,000

You might be interested in
A student bought 11 pencils and a pad of paper.
dusya [7]

Answer:

bbv bcb vhmnkdjefkmkhgjfnmd

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
What's the Error?<br><br> 3+1(6+2)<br> 4(6-2)<br> 4(3)<br> 12
gulaghasi [49]
Yes 12 thats the error
5 0
3 years ago
M - 1 = 2 what do I need to do to solve.
andreyandreev [35.5K]

In order to solve this, start by adding 1 to both sides of the equation.


m-1=2

+1 +1

-----------

m=3


The solution to your equation is 3.


You can also check to see if this is true by replacing m with 3.

m-1=2

3-1=2

7 0
3 years ago
3n - 17 = -50<br> two step equations help please
likoan [24]

Answer:

n = -11

Step-by-step explanation:

3n - 17 = -50

⇒ 3n = -33

⇒ n = -11

8 0
2 years ago
Read 2 more answers
SOMEONE PLZ HELP ME 1. What was the theoretical probability of collecting a specific dinosaur, such as a Velociraptor, in a sing
VMariaS [17]
3 multiply by 2x -5 it equal 27
8 0
3 years ago
Other questions:
  • Solve for x: 2|2x-2| +4=20
    12·1 answer
  • Select which type of polygon this figure is, and determine whether it's convex or concave.
    6·2 answers
  • Please help me with the correct answer
    9·2 answers
  • A vendor sells fifteen sweatshirts for $15 each, thirty t-shirts for $10 each, and forty hats for $8 each. What is the average p
    11·1 answer
  • If m∠1 = m∠2, then m∠1 is:
    9·1 answer
  • Which statement is correct about a lime and a point?
    5·1 answer
  • 2/7x+1/2x=−40/7−1/6x please explain step by step
    13·2 answers
  • A golf has a diameter of 2 inches. what is the volume of the golf ball in terms of pi
    14·2 answers
  • During track and field practice yesterday, Louie ran more than 1.6 miles but less than 1.75 miles. Which of the following could
    11·1 answer
  • The policyholder is really tight on cash and wants to trim down their insurance premiums so they can devote more of their budget
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!