Answer:
its (C) or (B) but my answer would be (B)
Step-by-step explanation:
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:
(-3,0) and (0,3)
Step-by-step explanation:
The solution to the system of equation is where the two graphs intersect
The intersect at two points
(-3,0) and (0,3)
6+5=11+5=16+5=21
3+6=9+6=15+6=21
It will take Marco and Sophie 3 hours to get the same amount of money. The amount of money they will have will be $21.