I have a question and searched about at google and found an answer which I don't make sure. If there is 26 letters and 10 digits;
my answer is:
first letter: 1 way(which is A)
second letter: 26 way
third letter: 26 way
first digit: 1 way(which is 1)
second digit 1 way(which is 2)
third digit: 10...
8 friends are playing a tennis game together. How many different doubles games of tennis can they play?
The Attempt at a Solution
Well, I solved this problem by saying: we choose a group 4 people from 8 to play, so order is not important...
Counting problems are a very tough subject to me, so if someone could give me tips, examples explaining what's really happening, that would be great.
I know what permutations, variations, combinations, ... are. The problems involving only one of those...