Question

Use the combination formula below to find the number of outcomes when n = 6 and r = 3. n!

(n−r)!r!

Answer 1

20

Explanation:

Put the numbers into the formula and do the arithmetic.

`n\text{C}r=(n!)/((n-r)!r!)\\\\6\text{C}3=(6!)/((6-3)!3!)=(6\cdot 5\cdot 4)/(3\cdot 2\cdot 1)=5\cdot 4\\\\\boxed{6\text{C}3=20}`