30/01/2013 - Four in a Row (**)

This puzzle is rated 2 star (medium).

Description

For this puzzle you need to draw or visualise a 4 by 4 grid.

Puzzle
On the gird, how many squares can be shaded without having 4 shaded squares connected in a straight line (either horizontally, vertically or diagonally)?

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.

27/01/2013 - Pool Balls (**)

This puzzle is rated 2-star (medium).

Description

A cloth bag contains a single red pool ball. 

A second pool ball is chosen at random in such a way that it is equally likely to be a red or a yellow ball. The ball is added to the bag, the bag is shaken, and a ball is drawn at random. 

The withdrawn ball proves to be a red.

Puzzle

What is the probability that the ball remaining in the bag is also a red?

Check the solutions page for the correct answer.

26/01/2013 - Connected Circles II (***)

This puzzle is rated 3 star (hard).

Description
Build the grid shown below.

Puzzle
Place the numbers 1, 2, 3, 4, 5 and 6 into the six circles so that the numbers next to each circle are the sum totals of all of the connected circles.

For example:
The diagram shown below, can be completed, by using the numbers 1,2 and 3.

With the correct answer being.

Check the solutions page for the correct answer.