With the letters A, B, C, D, E, F, G.
a. How many strings can you make with 5 characters?
b. maximum 7 characters?
c. 4 characters, no repetition?
d. sorted strings without repetition. Sorted = alphabetical.
e. sorted strings with 7 characters.
I think I got a-d solved, so no need to explain those too much. However, please do explain how you got the answer for e, in a way I could figure out similar questions later.
I tried messing around some with 'e' and got a question equal to something a machine told me. Used formula C(m+n-1, n-1) (C(7+7-1, 7-1) = 1716) to get there. I'm not sure why what I did was right though.
Thanks for any reply. Sorry of I messed up anything about this question.