Loading Calculator...
Please wait a moment
Please wait a moment
Calculate the number of ways to choose r items from n items where order doesn't matter.
Also written as nCr, C(n,r), nCr, or "n choose r"
Use combinations when order doesn't matter (like choosing a team). Use permutations when order matters (like arranging a schedule). Remember: combinations are always smaller because they don't count rearrangements.
Pascal's Triangle is a triangular array where each number is C(row, position). It shows that each value equals the sum of the two numbers above it, which is the property C(n,r) = C(n-1,r-1) + C(n-1,r).