Permutation or Combination

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

When would you use combinations instead of permutations?

Back

Use combinations when the order of selection does not matter, such as choosing team members.

Front

When would you use permutations instead of combinations?

Back

Use permutations when the order of selection is important, such as arranging books on a shelf.

Front

How many ways can you arrange 3 books on a shelf? (Books A, B, C)

Back

6 ways: ABC, ACB, BAC, BCA, CAB, CBA.

Front

How many ways can you choose 2 fruits from a selection of 5? (Fruits: Apple, Banana, Cherry, Date, Elderberry)

Back

10 ways: AB, AC, AD, AE, BC, BD, BE, CD, CE, DE.

Front

What is the formula for permutations of n objects taken r at a time?

Back

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

Front

What is the formula for combinations of n objects taken r at a time?

Back

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

Front

If you have 5 different shirts and want to wear 2, how many different outfits can you create?

Back

10 outfits (combinations) since the order of shirts does not matter.

Front

If a password consists of 4 letters chosen from 26 letters of the alphabet, how many different passwords can be formed?

Back

456976 passwords (permutations) since the order of letters matters.