Permutations v Combinations

Front

What is a permutation?

Back

A permutation is an arrangement of objects in a specific order. The order matters in permutations.

Front

What is a combination?

Back

A combination is a selection of objects where the order does not matter.

Front

What does 10P5 mean?

Back

Permutations with 10 choices and 5 positions.

Front

How do you calculate permutations?

Back

Permutations can be calculated using the formula nPr = n! / (n - r)!, where n is the total number of items, and r is the number of items to arrange.

Front

How do you calculate combinations?

Back

Combinations can be calculated using the formula nCr = n! / (r! * (n - r)!), where n is the total number of items, and r is the number of items to choose.

Front

What is 8! (8 factorial)?

Back

8! = 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 40320.

Front

How many ways can you arrange 7 students in a row?

Back

There are 5040 ways to arrange 7 students in a row (7!).

Front

If there are 18 runners, how many ways can you place the top 3?

Back

There are 4896 ways to place the top 3 runners (18P3).

Front

What is the difference between permutations and combinations?

Back

The key difference is that permutations consider the order of selection, while combinations do not.

Front

How many ways can you choose 3 players from a team of 17?

Back

There are 680 ways to choose 3 players from a team of 17 (17C3).