20/03/2013 - Dominoes 2 (**)

This puzzle is rated 2 star (medium).

Description

Use above and imagine (or use) 4 dominoes labelled 6:6, 6:2, 2:5, 3:1, 1:5, 4:6, 5:6, 3:3 and 2:1.

Puzzle
Place the dominoes 6:6, 6:2, 2:5, 3:1, 1:5, 4:6, 5:6, 3:3 and 2:1, so that the correct numbers are covered by the dominoes.

Check the solutions page for the correct answer.

05/03/2013 - Adding It Wrong! (**)

This puzzle is rated 2 star (medium).

Description

This is an additional table that seems to follow a different pattern.

Puzzle
Work out the missing number.

Check the solutions page for the correct answer.

28/02/2013 - Coin Jumping (***)

This puzzle is rated 2 star (hard).

Description

Layout 10 coins in a row.

Coins must jump two places and over exactly two coins each time (either one coin in each of the two spaces it is jumping or over two coins in one place and zero coins in the other place).  This rule has been shown above.

Puzzle
Using the rules given above end with 5 stacks of 2 coins.

Check the solutions page for the correct answer. 

27/02/2013 - Three Cups (*)

This puzzle is rated 1 star (easy).

Description

Three cups are placed on a table, with the outer two facing up and the middle one facing down.

Puzzle

Flipping two cups each move, make three moves to have all the cups facing up.

Check the solutions page for the correct answer.

20/02/2013 - Toads and Toadstools (***)

This puzzle is rated 3 star (hard).

Description

Here is a class puzzle.

Two white toads and two black toads are sat on toadstools (that can only fit one toad on each).  There are 8 toadstools arranged in a square (3 by 3, with the middle empty), as shown above.  The white toads are sat in the corners at the top and the black toads in the corners at the bottom.

The toads want to swap places, but they can only jump according to the rules of a knight in chess (that is 2 squares up or down and one to side, or two squares to the side and one square up or down).

Puzzle
Swap the toads positions in as few moves as possible.

Check the solutions page for the correct answer.

16/02/2013 - When? 1 (*)

This puzzle is rated 2 star (easy).

Description
Three days ago, yesterday was the day before Sunday.

Puzzle
What day will it be tomorrow?

Check the solutions page for the correct answer

12/02/2013 - Carriages (**)

This puzzle is rated 2 star (medium).

Description

Mr and Mrs Green, Mr and Mrs Brown and Mr and Mrs White sit in a railway carriage.

There are three seats on each side of the carriage, with a door on one side.

No man sits next to, or opposite, his wife.

No man sits next to another man.

Mr Green is neither next to, nor opposite, Mrs Brown.

Mr White is not by the door.

Puzzle
Where is each person sitting?

Check the solutions page for the correct

09/02/2013 - Trains (**)

This puzzle is rated 2 star (medium).

Description

The red engine is behind the yellow engine.
The yellow engine is behind the green engine.
The blue engine is between the purple engine and the red engine.
The orange engine is last.

Puzzle
Put the engines in order.

Check the solutions page for the correct answer.

08/02/2013 - Dominoes 1 (*)

This puzzle is rated 1 star (easy).

Description

Use above and imagine (or use) 4 dominoes labelled 3:4, 5:3, 4:2 and 3:2.

Puzzle
Place the dominoes 3:4, 5:3, 4:2 and 3:2 onto the grid above, so that each side has numbers summing to 10.

Check the solutions page for the correct answer.

03/02/2013 - Fifteen (*)

This puzzle is rated 1 star (easy)

Description

Write down the numbers 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

Puzzle
How many ways can you add 3 of the number 0 to 9 (inclusive) to make 15?

Check the solutions page for the correct solution.

31/01/2013 - Zero (**)

This puzzle is rated 2 star (medium).

Description

Create a triangle with 4 squares on each side (9 squares in total) like the one shown above.

Puzzle
Put the number -4, -3, -2, -1, 0, 1, 2, 3 and 4 into the squares so that each side equals 0.

Check the solutions page for the correct solution.

29/01/2013 - Guess My Number (*)

This puzzle is rated 1-star (easy).

Description

1. I am a three digit number.
2. I am divisible by 5.
3. My digits add up to 8.
4. The tens digit is smaller than hundreds digit.
5. I am less than 300.

Puzzle
Find the number from the above clues.

Check the solutions page for the correct answer.

28/01/2013 - Bridge Walk (**)

This puzzle is rated 2 star (medium).

Description

A group of 4 people are walking through the jungle and come across an old wooden bridge.

It is dark and they only have one torch between them all, and they need to light the path when crossing the bridge.

Unfortunately, as it is an old bridge, no more than 2 people can walk on the bridge at any one time - otherwise it will collapse.

Some walkers are faster than others at crossing the bridge:

• Amie takes 1 minute to cross
• Ben takes 2 minutes to cross
• Clare takes 5 minutes to cross
• Dean takes 10 minutes to cross

Puzzle

Have all four people cross the bridge in the quickest time possible.

Check the solutions page for the correct solution.

23/01/2013 - Switcharoo (**)

This puzzle is rated 2 star (medium).

Description

The picture above shows a 3 by 3 board with two missing corners. 

There are 3 blue chips on the yellow part of the board and 3 yellow chips on the blue part of the board.

The rules are as follows:

• You can move a chip from one square to a square next to it if the square is empty.
• You can jump a chip over a different coloured chip next to it as long as you land in an empty space.
• You cannot move or jump diagonally.

Puzzle
The problem is to put the blue chips on the blue part and the yellow chips on the yellow part, i.e. switch the chips' positions.

Check the solutions page for the correct answer. 

21/01/2013 - 5 Digit Number (***)

This puzzle is rated 3 star (hard).

Description

If we put the digit 1 at the beginning of a 5 digit number we will get a number three times smaller than if we put the digit 1 at the end of the 5 digit number.

Puzzle
What is the 5 digit number?

Check the solutions page for the correct answer.

16/01/2013 - Heavy Apples (***)

This puzzle is rated 3 star (hard)

Description

Someone has mixed up some apples:

• There are 10 baskets containing apples.

• There are various amounts of apples in each basket ranging from 10 to 20.

• 9 of the baskets contain apples weighing 4 ounces each.

• 1 of the baskets contains apples weighing 5 ounces each.

• All the apples look the same.

• The equipment you have is a set of scales and an empty basket.

• It is late and the lorry is waiting to take the apples to market. You only have time to make one measurement using the scales.

Puzzle

How can you tell which basket has the 5 ounce apples in it?

Check the solutions page for the correct answer.

12/01/2013 - Die Hard Jugs (*)

This puzzle is rated 1 star (easy).

Description

This puzzle is taken from the film Die Hard With A Vengeance, where the characters John McClane and Zeus Carver open a briefcase only to discover that in doing so they have armed a powerful bomb. It will explode in a matter of minutes unless they can disarm it. Inside the briefcase there is a scale. They have at their disposal two jugs, like the ones shown above.  1 jug can hold exactly 5 litres of water and the other exactly 3 litres of water.  The water can be obtained from a nearby fountain.

Puzzle
Fill the 5 litre jug with exactly 4 litres of water.

Check the solutions page for the correct answer.

10/01/2013 - Pardoner's Tale (***)

This puzzle is rated 3 star (hard).

Description

Here is a classic puzzle from the Canterbury Tales, where a prisoner has to come up with a puzzle to be pardoned for his crime - and this was his creation.

Draw the grid above, making sure to leave the gap (missing line) at the bottom centre of the grid.

Puzzle
Starting at the prisoners location (the black square) make 15 connecting lines that do not cross and pass through all the other blank squares.

Check the solutions page for the correct answer.

08/01/2013 - Even Chocolates (**)

This puzzle is rated 2 star (medium)

Description

A box of chocolates is laid out in the mathematics department staff room.  There are 6 members of staff, who all take 1 chocolate each from the box, without moving any of the others.

Puzzle
Remove the 6 chocolates so that there is still an even number of chocolates on every horizontal, vertical and corner-to-corner diagonal.

Check the solutions page for the correct answer.

07/01/2013 - Bug Jump (***)

This puzzle is rated 3 star (hard).
 
Description

 

Three red bugs and three green bugs are playing a game on the board shown above. The red bugs and green bugs have to change places.

They are allowed to do the following:

• A bug may move from its spot along a line to an empty space as long as it doesn't pass over another bug.
• A bug that is in one of the corner spots may jump over another bug of a different colour provided it jumps in a straight line and lands in an empty space.

However, a bug cannot jump over a bug of the same colour.

Puzzle
What is the minimum number of moves to have the red and green bugs change places?

Check the solutions page for the correct answer.