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??
Ms. Sue, wouldn't it be 9^10? I think 0 wasn't included, so it would be 10 numbers not 9.....right???
so it would be 1,000,000,000???
http://www.jiskha.com/display.cgi?id=1311437782
I'm not sure.
Please post this as a New Question. That way a math tutor may be able to help you.
For social security numbers, 0 can be included.
n^r = 10^9, where n is the number of things to choose from, and you choose r of them (Repetition allowed, order matters)
But how about if repetition of digits are NOT allowed??
To determine how many different possible social security numbers are possible with repetition of digits, we need to consider the number of choices for each digit position.
Since each digit can be any number from 0 to 9, there are 10 choices for each of the nine positions. Therefore, the total number of possible social security numbers is found by multiplying the number of choices for each digit position:
10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 × 10 = 10^9
So, the correct answer is 10^9, not 9^10.