SOLUTION: Prove that there must be at least 2 students at a college with the same last four digits of a social security number So far, I've tried reasoning that there are 10 possible digi

Algebra ->  Permutations -> SOLUTION: Prove that there must be at least 2 students at a college with the same last four digits of a social security number So far, I've tried reasoning that there are 10 possible digi      Log On


   

Question 236899: Prove that there must be at least 2 students at a college with the same last four digits of a social security number
So far, I've tried reasoning that there are 10 possible digits, and i have to choose 4 of them, so it would be a combination/permutation of 10 choose 4. (i'm not sure which one it is though) and where do I go from there
Found 2 solutions by scott8148, edjones:
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
the four digits range from 0000 to 9999 ___ 10,000 possibilities

if there are more than 10,000 students at the school, then there has to be duplication

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
How many students at the college?