Using the fundamental counting theorem, we have that:
- 648 different area codes are possible with this rule.
- There are 6,480,000,000 possible 10-digit phone numbers.
- The amount of possible phone numbers is greater than 400,000,000, thus, there are enough possible phone numbers.
The fundamental counting principle states that if there are p ways to do a thing, and q ways to do another thing, and these two things are independent, there are ways to do both things.
For the area code:
- 8 options for the first digit.
- 9 options for the second and third.
Thus:

648 different area codes are possible with this rule.
For the number of 10-digit phone numbers:
- 7 digits, each with 10 options.
- 648 different area codes.
Then

There are 6,480,000,000 possible 10-digit phone numbers.
The amount of possible phone numbers is greater than 400,000,000, thus, there are enough possible phone numbers.
A similar problem is given at brainly.com/question/24067651
Answer:
-28
Step-by-step explanation:
-4(7)=-28
Answer:
Step-by-step explanation:
If you divide 33 by 11 it’ll be 3 so we can cross B off, and A too because it’s not a double digit
So that leaves us with C & D.
If we divided 222 and 11 it would leave us with 10 which doesn’t match 11, so that leaves us with D
(Sorry if I didn’t’t explain right )
3^5 is the same as 3*3*3*3*3. which is 243