Combination Calculator
Calculate combinations C(n,r) - the number of ways to select r items from n items where order doesn't matter. With or without repetition.
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Combination Calculator - Selections Where Order Doesn't Matter
Calculate combinations instantly with our easy-to-use calculator. Find the number of ways to select r items from n items where order doesn't matter. Perfect for probability, statistics, and lottery calculations.
What is a Combination?
A combination is a selection of items where the order doesn't matter. C(n,r) represents the number of ways to choose r items from a set of n items. For example, selecting 3 students from a class of 20 for a committee - the group (A,B,C) is the same as (C,B,A). Without repetition: C(n,r) = n!/(r!(n-r)!). With repetition: C(n+r-1,r).
Combination Formula
C(n,r) = n!/(r!(n-r)!)How to Use This Calculator
Combination Calculator Applications
Lottery Calculations
Calculate odds of winning lottery games and jackpots.
Team Selection
Find ways to form teams or committees from a group.
Menu Combinations
Calculate possible meal combinations from menu items.
Card Games
Determine possible hand combinations in poker and other games.
Frequently Asked Questions
In combinations, order doesn't matter (ABC = BAC). In permutations, order matters (ABC ≠ BAC). Use combinations when selecting a group, like choosing team members. Use permutations when arranging in order.