Puzzle 5
The river Pregel ran through the town of Konigsberg. In the river were two islands, connected to each other and the rest of the city by seven bridges.
The residents of Konigsberg challenged each other to walk through the city, and cross each of the seven bridges exactly once.
Can you find a path that they might have taken?
This is the 'Seven Bridges of Konigsberg' puzzle, tackled by Leonhard Euler in 1736.
Puzzle 6
A very long time ago, at the beginning of the week, I was given some money for my birthday.
On Monday, I spent a quarter of the money on clothes.
On Tuesday, I spent one third of the remaining money on music.
On Wednesday, I spent half of the remaining money on games.
Finally, on Thursday, I spent the last £12.50 on a book.
How much birthday money did I receive?
Puzzle 7
Which of the shapes are identical to the first one?
Puzzle Copyright © Robert A. Hartmann
Puzzle 8
Training Stars #1all logic puzzles
The first group of trainee astronauts are all sitting around the rectangular table, waiting to start their first day of training.
From the clues given below, can work out where everyone sits?
The seats are numbered clockwise, with Seat 1 next to Seats 2 and 8. Opposite pairs are Seats 1 & 5, 2 & 8, 3 & 7, and 4 & 6.
William is next to Alisa and Nick.
William is across from George.
Amanda is next to Sarah.
Sarah is across from Eric.
Nick is next to Eric.
Sydney is in Seat 4 and sits next to George.
George has a higher seat number than Sydney.
Alisa is not in Seat 2.
Puzzle Copyright © Randall Fine