Combinations of abcdefg that have at least 2 of ab or c. The Syntax of the function is as follows-. 4 6 displaystyle _ nC_ r frac 10 4 6.
161514 321 3360 6 560.
In other words choosing 3 balls out of 16 or choosing 13 balls out of 16 have the same number of combinations. So the number of combinations is equal to n n-kk. Remember the formula to calculate combinations is nCr n. Solve the equation to find the number of combinations.