6 phone numbers are possible for one area code if the first four numbers are 202-1
<u>Solution:</u>
Given that, the first four numbers are 202-1, in that order, and the last three numbers are 1-7-8 in any order
We have to find how many phone numbers are possible for one area code.
The number of way “n” objects can be arranged is given as n!
Then, we have three places which changes, so we can change these 3 places in 3! ways
Hence 3! is found as follows:
So, we have 6 phone numbers possible for one area code.
Answer:
The first one
Step-by-step explanation:
If you have any questions about the way I solved it, don't hesitate to ask me in the comments below ;)
Answer:
Step-by-step explanation:
Given : In a state where license plates contain six digits.
Probability of that a number is 9 = 
[Since total digits = 10]
We assume that each digit of the license number is randomly selected .
Since each digit in the license plate is independent from the other and there is only two possible outcomes for given case (either 9 or not), so we can use Binomial.
Binomial probability formula: 
, where n= total trials , p = probability for each success.
Let x be the number of 9s in the license plate number.
Then, the probability that the license number of a randomly selected car has exactly two 9's will be :
Hence, the required probability = 0.098415
100% of the original number
