View Full Version : Annoying Maths Puzzle

14th Apr 2005, 18:36
This was given to my 9 year old brother in school, and I have to admit I am having trouble.


> The castle walls are 100 years older than the church.

> When the church was 250 years old a new tower was built.

> 50 years before the tower was built, a moat was dug around the castle.

> Today, the tower is exactly half as old as the castle walls.

How long has the moat been there?

To help you get the answer, work out these answers in the correct order:

1) How many years are the walls older than the tower?
2) How old are the walls and the tower?

You should also be able to work out what year.....

1) The castle was built
2) The tower was built
3) The church was built


Very annoying indeed and if someone can come up with an answer, there will be muchass respectos


14th Apr 2005, 18:39
400 years old, but I won't include working as not to spoil the puzzle.

Onan the Clumsy
14th Apr 2005, 19:00
Yeah 400 years. but you'd have to look at the shape of the windows to tell what year it was built :8

Desert Dingo
14th Apr 2005, 19:03
Yes. It's 400 years. If you plot everything on a timeline, everything will fall into place without the need to manipulate any equations.

Edited 'cause Onan did his sums again and got it right this time

14th Apr 2005, 19:52
Come on ! :suspect:

14th Apr 2005, 21:03
Facts translate to:

1. Castle = Church +100
2. Tower = Church - 250
3. Moat = Tower + 50
4. Tower = Castle/2

substitute 2 into 4 gives Castle/2 = Church - 250
which is the same as saying Castle = 2 Churches - 500
substitute this into 1 giving 2 Churches - 500 = Church + 100
giving the answer that Church = 600
put this into 2 gives the Tower to be 350
put this into 3 gives the Moat to be 400
and then Castle is 700 years old

Onan the Clumsy
14th Apr 2005, 21:40

If the walls were built in the year 0
the church was built in the year 100
the moat was built in the year 300
and the tower in the year 350

so today must be the year 700 for the walls to be twice as old as the tower

which means the moat was built 400 years ago.

Ergo quipt es-summus con summas, quod erot demonstrandum

14th Apr 2005, 22:20
Drawing the time line, I think the moat is a complete red herring.
I get the walls>tower 350 years, so the tower to now=350 years, so the walls is 700 years old.
So the castle was built in 1305
The tower was built in 1655
The church was built in 1405

Why nobody answer the damn questions? The moat doesn't come up again. I want all your GCE Maths 'O' level certificates back for disposal please!

14th Apr 2005, 22:23
Yeah, 700, 600, 400, 350. Piece of cake.
No equations needed - just draw the timeline.

Onan the Clumsy
14th Apr 2005, 23:28
I think the moat is a complete red herring Actually no. It's a wide, water filled trench that surrounds the castle and is designed to keep out invaders.

But that's not important now.

15th Apr 2005, 02:13
OK, hands up everyone here who likes a smartass?? ;)

15th Apr 2005, 07:47
Drawing the time line, I think the moat is a complete red herring - although I prefer Onan's answer, there is always RTFQ:D