Beginner
Discrete Mathematics & Math
Q15 / 100
What is a combination?
Correct! Well done.
Incorrect.
The correct answer is B) An unordered selection of r items from n: C(n,r) = n! / (r!(n-r)!)
B
Correct Answer
An unordered selection of r items from n: C(n,r) = n! / (r!(n-r)!)
Explanation
C(n,r) = ₙCᵣ = "n choose r" counts subsets of size r. Choosing 3 from 5 people for a committee: C(5,3) = 10. Order doesn't matter: {A,B,C} = {C,A,B}.
Progress
15/100