Hi all, i'm new to the forum so i hope this is the correct place to post this question. If i have 15 numbers 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, how do i figure out how many different sets of 3 numbers together i can make from the 15, like 1,2,3 or 1,6,8 for example. No duplicates so for example 1,2,3 would be the same as 3,2,1 or 1,3,2 etc. Just every number with every other number once in sets of 3 numbers. How many combinations are there without replicating any? If you could explain how you got the answer too that would be great. TIA for the help, i appreciate it. Take care.