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
We know there are 4 quarts in a gallon, so how many quarts in 2.5 gallons anyway?
Answer:
(4-1)^5-2
Step-by-step explanation:
The quantity means parenthesis, around four minus one, (closed quantity), all raised to the power (exponent) five minus 2
Answer: 1. 140 times
Step-by-step explanation:
First, you would subtract 29.95 from 55.50, and you get 25.55. because 5 people went, and the cost for each was the same, you would divide 25.55 by five, and get $5.11 per person.