Combinations and Permutations

Front

What is a combination?

Back

A selection of items from a larger set where the order does not matter.

Front

What is a permutation?

Back

An arrangement of items from a larger set where the order does matter.

Front

How many distinct combinations can be formed with 7 digits using numbers 0 through 5?

Back

279936

Front

What does ₁₀P₅ represent?

Back

Permutations with 10 choices and 5 positions.

Front

How many different bicycle license plates can be formed with 2 letters followed by a 1-digit number?

Back

6760

Front

How many possible three-digit area codes can be created if the first digit can be 2-9, the second can be 0 or 1, and the third can be 0-9?

Back

160

Front

What is the formula for combinations?

Back

C(n, r) = n! / (r!(n-r)!) where n is the total number of items and r is the number of items to choose.

Front

What is the formula for permutations?

Back

P(n, r) = n! / (n-r)! where n is the total number of items and r is the number of items to arrange.

Front

Is selecting a lead and an understudy for a school play a permutation or a combination?

Back

Permutation.

Front

If you have 5 books and want to arrange 3 of them, how many different arrangements can you make?

Back

60 (P(5, 3) = 5! / (5-3)! = 60).