Permutation and 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

How many 2-digit numbers can you make using the digits 1, 2, 3, & 4 without repeating the digits?

Back

12

Front

How many different ways can first, second, and third prize be awarded among 6 different organizations?

Back

120

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)! where n is the total number of objects and r is the number of objects to arrange.

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)!] where n is the total number of objects and r is the number of objects to choose.

Front

In how many ways can you choose 3 students from a group of 10?

Back

C(10, 3) = 120 ways.

Front

If you have 5 different books, how many ways can you arrange them on a shelf?

Back

5! = 120 ways.

Front

What is the difference between permutations and combinations?

Back

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

Front

If a pizza place offers 3 types of crust, 4 types of sauce, and 5 toppings, how many different pizzas can be made?

Back

60 different pizzas (3 x 4 x 5).