Social security numbers have the form XXX-XX-,
where each X is a digit. How many unique social security
numbers are possible?
A) 100 million
B) almost 400 million
C) 1 billion
D) over 3 billion

Pamela chose B as the correct answer. How did she get that answer?

Please answer both parts.

there is only a certain amount of numbers  

i hope this helped you

C

Step-by-step explanation

So you take the amount of digits total (which is 9) and the highest number you can make is 999,999,999 so basically everything between 000,000,0001 and 999,999,999 is a possible unique social security number. So its closest to 1 billion.

Pamela got B since the only logical explanation i can think of is that she rounded  incorrectly

12cm

the answer is d

what is the answer to this