Solve:

6C3

There are different methods to solve this problem, but one common way is to use the formula for combinations:

nCr = n! / r!(n-r)!

where n is the total number of items, r is the number of items to choose, and (!) denotes the factorial function, which means the product of all positive integers up to that number.

For 6C3, we have:

n = 6 and r = 3

So the formula becomes:

6C3 = 6! / 3!(6-3)! = 6 x 5 x 4 / 3 x 2 x 1 = 20

Therefore, there are 20 ways to choose 3 items out of 6, assuming that order does not matter and repeats are not allowed.