Colin James Physics - Logic puzzles.
Last updated: 25th June 2013.
Logic puzzles.
These are general logic puzzles - not Physics puzzles, but they should be challenging and fun (just like Physics).
If you know what you are looking for in a puzzle or have done a similar one before you may find an easier puzzle harder or a harder one straightforward.
So it its worth scanning through the different categories.
When you click on a puzzle it will appear below (and the screen will move down to show the puzzle) with a solution further down the screen.
Easier puzzles.
Running puzzle.
Tennis puzzle.
Water puzzle.
Walking puzzle.
Harder puzzles.
Spending puzzle.
Cakes puzzle.
Ages puzzle.
Chess puzzles.
Chess puzzle 1.
Chess puzzle 2.
Chess puzzle 3.
Chess puzzle 4.
Chess puzzle 5.
Tennis puzzle.
In a group of people 75% play tennis and 55% play squash.
What is the minimum number of people who play both tennis and squash?
Solution
Solution
Solution
Solution
Solution: Tennis puzzle.
The minimum number of people who play both tennis and squash is 30%.
Explanation.
To simplify this puzzle I think of a group of 100 people and try and match up the group of tennis players with squash players.
The tennis players are one block (of length 75) and the squash players are a second block (of length 55).
The two blocks are contained within a frame of length 100 (maximum number of people) and I then slide the two blocks so they overlap.
If I overlap the two blocks completely I get the maximum number who play both games as 55 with 25 who play neither game.
If I slide the squash player block so that it occupies the space between 75 and 100 I get the minimum number who play both games as 30 (75 -45).
As I am working with 100 people the figures are already in percentages (%).
So the minimum number who play both games is 30%.
End of page.