SOLUTION: Four-Digit Number. How many four-digit numbers can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 if the first digit cannot be 0? Repeated digits are allowed.

Algebra ->  Permutations -> SOLUTION: Four-Digit Number. How many four-digit numbers can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 if the first digit cannot be 0? Repeated digits are allowed.       Log On


   

Question 413523: Four-Digit Number. How many four-digit numbers can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 if the first digit cannot be 0? Repeated digits are allowed.

Found 2 solutions by MathLover1, jilalbenkad:
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
9 choices for first digit (the first digit cannot be 0) and 10 choices for remaining three digits
9%2A10%2A10%2A10+=+9000+

Answer by jilalbenkad(2) About Me  (Show Source):
You can put this solution on YOUR website!
9*(10)^3= 9000