Combinations C(n,r)

n (total items)

r (items to choose)

120

Number of Combinations

C(n,r) = n! / (r!(n-r)!)

Calculation Steps:

C(10,3) = 10! / (3!(10-3)!)

= 3,628,800 / (6 × 5,040)

= 120

Common Examples:

Choose 2 people from 5C(5,2) = 10

Lottery (6 from 49)C(49,6) = 13,983,816

Poker hands (5 from 52)C(52,5) = 2,598,960