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andijo76
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?
There is a possibility of 10 numbers in each place. There are 9 places in a social security number (123-456-789)… 10^9=10x10x10x10x10x10x10x10x10=1 billion =1 billion combinations is this right?????
Can u have zero as ur first digit?
I believe 0 is a valid first digit.
You calculate it with the formula 10*10*10*10, since each of the four codes has 10 possible digits. Social security numbers are the same. You specified that numbers and letters can not be repeated. Therefore the 3 numbers will be 10*9*8. The two letters will be 26*25. Therefore the total possibilities will be 10*9*8*26*25.