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.
Ages puzzle.
I am four times as old as you were when I was the same age as you are now. I am fifty six (56) years old, how old are you?
Solution
Solution
Solution
Solution
Solution: Ages puzzle.
The answer is: You are now 35 years old.
Explanation.
We need to work out how old you are now which we will call X years old.
I am 56 now, so you were 56/4 = 14 at some time in the past when I was the same age as you are now (i.e. I was X years old when you were 14).
You are now X years old and now is (X - 14) years after the time when you were 14.
In the same number of years (from when you were 14) I have increased my age from X years old to 56.
The number of years from me being X to me being 56 is (56 - X) years and this is the same number of years between when you were 14 and now (X - 14).
The number of years since you were 14 (X - 14) is the same as the number of years since I was X (56 - X), so:
(X - 14) = (56 - X)
2X = 56 + 14
2X = 70
X = 70/2 = 35
You are now 35 years old.
End of page.