Permutations and 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. It focuses on the group rather than the arrangement.

Front

How do you calculate the number of permutations of n objects taken r at a time?

Back

The formula is P(n, r) = n! / (n - r)!.

Front

How do you calculate the number of combinations of n objects taken r at a time?

Back

The formula is C(n, r) = n! / (r!(n - r)!).

Front

What is the value of 5! (5 factorial)?

Back

5! = 5 × 4 × 3 × 2 × 1 = 120.

Front

What is the value of 0! (0 factorial)?

Back

0! = 1 by definition.

Front

If a team of 10 players needs to choose 4 players for a match, which formula do you use?

Back

Use the combination formula: C(10, 4).

Front

If the order of selection matters, which concept do you apply?

Back

You apply permutations.

Front

What is the difference between permutations and combinations?

Back

Permutations consider the order of selection, while combinations do not.

Front

How many ways can you arrange the letters in the word 'MATH'?

Back

There are 4! = 24 ways to arrange the letters.