EASY
AS and A Level
IMPORTANT
Earn 100

Two students are asked to find how many ways there are to plant two trees and three bushes in a row. The first student gives 5!=120, and the second gives 5!2!×3!=10. Decide who you agree with and explain the error made by the other student.

Important Questions on Permutations and Combinations

EASY
AS and A Level
IMPORTANT

Ten coins are placed in a row on a table, each showing a head or a tail.

How many different arrangements of heads and/or tails are possible?

EASY
AS and A Level
IMPORTANT

Ten coins are placed in a row on a table, each showing a head or a tail.

Find how many arrangements have five heads and five tails showing.

EASY
AS and A Level
IMPORTANT

Ten coins are placed in a row on a table, each showing a head or a tail.

Of the total arrangements, find how many have more heads than tails showing.

EASY
AS and A Level
IMPORTANT
There are 420 possible arrangements of all the letters in a particular seven-letter word. Give a description of the letters in this word.
EASY
AS and A Level
IMPORTANT

Find the number of distinct five-letter arrangements that can be made from:

two As and three Bs

EASY
AS and A Level
IMPORTANT

Find the number of distinct five-letter arrangements that can be made from:

two identical vowels and three Bs

EASY
AS and A Level
IMPORTANT

Find the number of distinct five-letter arrangements that can be made from:

Two identical vowels and any three identical consonants.

EASY
AS and A Level
IMPORTANT

Find how many five-digit numbers can be made using the digits 2,3,4,5 and 6 once each if:

there are no restrictions