An online calculator to calculate the number of combinations of \( n \) elements taken \( r \) a the time whose formula is given below.

Formula for the Number of Combinations

The number of combinations of \( n \) objects taken in groups of \( r \) objects at the time is given by
\[ n C r = C(n , r) = \dfrac{n!}{(n-r)! r!} \]

Use of Combinations Calculator

1 - Enter the positive integers \( n \) (total number of objects) and \( r \) (the number of objects in each group) and press "Calculate Combinations".