Math Formulas
Combination Formulas
The number of all combinations of n things, taken r at a time is :
$\text{C} \left ( \text{n},\text{r} \right )={^\text{n}\text{C}_\text{r}}= \dfrac{\text{n}!} {\left ( \text{n}-\text{r} \right )!~ \text{r}!} $
Where,
n, r are non negative integers and r ≤ n.
! is the factorial operator.
Factorial :
$\text{n}!=\text{n}\;(\text{n}-1)\;(\text{n}-2)$ $(\text{n}-3)\;(\text{n}-4)\;... $