Permutations and Combinations Quiz

What is a permutation?

• A selection of objects where order does not matter

• A selection of objects where order is important

• An arrangement of objects where order is important

• An arrangement of objects where order does not matter

According to the fundamental counting principle, if one event can occur in m ways and another in n ways, how many ways can both events occur?

• m / n

• m * n

• m - n

• m + n

What does the factorial of a number represent?

• The sum of all positive integers up to that number

• The product of all positive integers up to that number

• The difference of all positive integers up to that number

• The division of all positive integers up to that number

How is 4 factorial (4!) calculated?

• 4 * 3 * 2 * 1

• 4 / 3 / 2 / 1

• 4 + 3 + 2 + 1

• 4 - 3 - 2 - 1

In permutations, what does 'n objects taken r at a time' mean?

• Using r objects in n different ways

• Using all n objects in every arrangement

• Using r objects from n in every arrangement

• Using n objects in r different ways

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

• r! / n!

• (n - r)! / n!

• n! / (n - r)!

• n! / r!

What distinguishes a combination from a permutation?

• Order is important in combinations

• Order is not important in combinations

• Combinations use all objects

• Combinations are always larger than permutations

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

• r! / (n! * (n - r)!)

• n! / (r! * (n - r)!)

• (n - r)! / (n! * r!)

• n! / (n - r)!

In a probability problem using combinations, what is the probability of a specific outcome?

• The difference between favorable and total outcomes

• The number of favorable outcomes divided by the total possible outcomes

• The sum of favorable and total outcomes

• The number of total outcomes divided by the favorable outcomes

When should you use permutations instead of combinations?

• When the order of selection does not matter

• When the number of objects is small

• When the number of objects is large

• When the order of selection matters