Respuesta :

If you include all zeroes, then it should be 1,000,000,000. Otherwise it’s 999,999,999.

Think of how between 0-9 theres 10 numbers, and use that logic towards 000000000-999999999

Following are the calculation to the unique id number:

Given:

assigned unique id= 9 digits

To find:

unique id's=?

Solution:

Unique numbers= 1,2,3,4,5,6,7,8,9,0

So,

[tex]\to n=10[/tex]

unique number [tex]r=9 \ digits[/tex]

Using formula:

[tex]\to ^nP_r=\frac{n!}{n-r!}\\\\\to ^{10}_{P_{9}}=\frac{10!}{(10-9!)}\\\\[/tex]

       [tex]=\frac{10!}{(10-9!)}\\\\=\frac{10!}{(1!)}\\\\=\frac{10!}{1}\\\\=3628800\\\\[/tex]

Therefore, the final answer is "3628800".

Learn more:

brainly.com/question/364021