SOLUTION: A telephone company wants to create as many 7-digit phone numbers as possible without changing the first 3 digits. How many phone numbers can be created?

Question 574411: A telephone company wants to create as
many 7-digit phone numbers as possible
without changing the first 3 digits. How
many phone numbers can be created?
Found 2 solutions by nyc_function, sudhanshu_kmr:
Answer by nyc_function(2741) (Show Source): You can put this solution on YOUR website!
7P3 = 7!/(7 - 3)!

7P3 = 5040/4!

7P3 = 5040/24

7P3 = 210 phone numbers can be created.
Answer by sudhanshu_kmr(1152) (Show Source): You can put this solution on YOUR website!

According to question first 3 digits are fixed.
Number of ways to create 4 digit numbers = 10* 10*10*10 = 10000
(repetition of digits are allowed on phone number)

if any doubt, feel free to contact....
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