If you intepret the string of digits as numbers, then the numbers are between 10^8 and 10^9 -1, so the answer is:
10^9 - 1 - (10^8 - 1) =
10^9 - 10^8
Social Security Numbers A social security number consists of nine digits. How many different social security numbers are possible if repetition of digits is permitted?
Is it 9^10?? 10 numbers correct?
5 answers
oooooh i totally got lost on this....
We can use the rule of product:
the first number we choose from 1 to 9,
the 2nd, 3rd,...,9th from 0 to 9.
So the number is
9*10*10*...*10=9*10^8 (=10^9-10^8)
the first number we choose from 1 to 9,
the 2nd, 3rd,...,9th from 0 to 9.
So the number is
9*10*10*...*10=9*10^8 (=10^9-10^8)
SO ITS 1000000000-100000000 = 900000000??
yes
6 answers