Help me with statistics

Just looked at my HW and i have very little idea to how solve even the first problem.

So, if someone here has any idea how to solver for "Permutations" and "Combinations" please explain it to me.

Here is one of the problems:

An employer wants to give each employee an ID, defined as two letters followed by 4 number(e.g., TY751). Solve for the maximum number of employees that the firm can hire and still give each a unique ID?:ugh:


Thanks, Taras

 

come on guys i need some help here.

 

Here is my guess:
26 letters for the first character
26 letters for the second character
10 numbers for the third character (using 0-9 as the numbers)
10 numbers for the fourth character
10 numbers for the fifth character
numbers for the sixth character
26x26x10x10x10x10=6,760,000???
Reminder! Only a guess!!!

 

0-9 is actually 10 possible numbers. So by your method it would be 6,760,000, though for some reason I don't think that's the formula.

 

My bad! Was only a guess

 

shouldn't this be permutation formula: nPr= n!/(n-r)! ?
I am really confused here.

 

its YOUR homework..do it yourself you bum.

 

dude, I am just asking for some help. Dont want to help? Dont say $hit then.

 

No, the above solution is correct since order is important.

 

lol, ask the prof imo.

 

Yeah, i am going to get some help later today from another prof.
Thanks for all the help guys.

 

e=mc2

 

figured it out.

 

a2+b2=c2

 

Nerd alert!

 

so wats the answer

 

The first solution (post #3) is correct.