... ran into is a cool logic test.

I always liked to solve riddles - as long as they aren't almost impossible that is. So when I ran into this one, of course I immediately accepted the challenge.

I actually solved this in less than two minutes and felt remarkably proud of myself after it. It's actually quite easy, so if you don't want to know the answer to it before you solve it yourself, don't read any further.

Here's how I solved it.

First off I looked at all the numbers that equal zero, and than looked at the numbers that have these incorporated in them. For example if you take 1111=0 than look at the 7111=0 the first thing that comes to mind is that you should take each number and give it a value. So by doing that you'll get that the number 1 equals zero and number 7 equals zero as well. So if 1 and 7 is zero and you look at 2172=0 you'll get that 2 equals zero as well. And so it comes down to that single 8. If you look at 0000=4 that means that zero equals one, and if you look at 9313=1 you'll get that 9 is 1 as well. Now it only remains to check out the first number 8809=6 to come to the conclusion that 8 =2 because 2+2+1+1=6. Thus the questioned number 2581 will in the end become a simple 2.

All right guys, here's another one I actually solved a couple of times already, just for the fun of it (and because I couldn't remember the answer).

Apparently Einstein made quite a couple of logic puzzles in his life, and this is one of it. It's a grid puzzle - if you don't know what that is click this link for an explanation.

It is said that this quiz was made up by the famous physicist and according to him 98% will not solve it.

There is a row of five different color houses. Each house is occupied by a man of different nationality. Each man has a different pet, prefers a different drink, and smokes different brand of cigarettes.

The Brit lives in the Red house.
The Swede keeps dogs as pets.
The Dane drinks tea.
The Green house is next to the White house, on the left.
The owner of the Green house drinks coffee.
The person who smokes Pall Mall rears birds.
The owner of the Yellow house smokes Dunhill.
The man living in the center house drinks milk.
The Norwegian lives in the first house.
The man who smokes Blends lives next to the one who keeps cats.
The man who keeps horses lives next to the man who smokes Dunhill.
The man who smokes Blue Master drinks beer.
The German smokes Prince.
The Norwegian lives next to the Blue house.
The man who smokes Blends has a neighbor who drinks water.

Who has fish at home?

All right, it might take some time to figure this one out, but it's actually not that hard. This time I won't post the answer to it because this puzzle is all over the internet and it's answer is too - though I've yet to find a decent enough explanation to how it was solved. And since I would need to solve it again for me to be able to post the loooong path my mind went for a stroll on (I still don't remember how I did it), and I'm not about to spend half my day on it again I'm taking the coward's way out.

Another example of hard grid puzzles (just like Einstein's) was published in the QUIZ 11/1986.
Eight married couples meet to lend one another some books. Couples have the same surname, employment and car. Each couple has a favorite color. Furthermore we know the following facts:

  1. Daniella Black and her husband work as Shop-Assistants.
  2. The book "The Seadog" was brought by a couple who drive a Fiat and love the color red.
  3. Owen and his wife Victoria like the color brown.
  4. Stan Horricks and his wife Hannah like the color white.
  5. Jenny Smith and her husband work as Warehouse Managers and they drive a Wartburg.
  6. Monica and her husband Alexander borrowed the book "Grandfather Joseph".
  7. Mathew and his wife like the color pink and brought the book "Mulatka Gabriela".
  8. Irene and her husband Oto work as Accountants.
  9. The book "We Were Five" was borrowed by a couple driving a Trabant.
  10. The Cermaks are both Ticket-Collectors who brought the book "Shed Stoat".
  11. Mr and Mrs Kuril are both Doctors who borrowed the book "Slovacko Judge".
  12. Paul and his wife like the color green.
  13. Veronica Dvorak and her husband like the color blue.
  14. Rick and his wife brought the book "Slovacko Judge" and they drive a Ziguli.
  15. One couple brought the book "Dame Commissar" and borrowed the book "Mulatka Gabriela".
  16. The couple who drive a Dacia, love the color violet.
  17. The couple who work as Teachers borrowed the book "Dame Commissar".
  18. The couple who work as Agriculturalists drive a Moskvic.
  19. Pamela and her husband drive a Renault and brought the book "Grandfather Joseph".
  20. Pamela and her husband borrowed the book that Mr and Mrs Zajac brought.
  21. Robert and his wife like the color yellow and borrowed the book "The Modern Comedy".
  22. Mr and Mrs Swain work as Shoppers.
  23. "The Modern Comedy" was brought by a couple driving a Skoda.

Is it a problem to find out everything about everyone from this information?

Here's another one for you guys... though this one is amazingly easy.
There are 5 ships in a port.
  1. The Greek ship leaves at six and carries coffee.
  2. The ship in the middle has a black chimney.
  3. The English ship leaves at nine.
  4. The French ship with a blue chimney is to the left of a ship that carries coffee.
  5. To the right of the ship carrying cocoa is a ship going to Marseille.
  6. The Brazilian ship is heading for Manila.
  7. Next to the ship carrying rice is a ship with a green chimney.
  8. A ship going to Genoa leaves at five.
  9. The Spanish ship leaves at seven and is to the right of the ship going to Marseille.
  10. The ship with a red chimney goes to Hamburg.
  11. Next to the ship leaving at seven is a ship with a white chimney.
  12. The ship on the border carries corn.
  13. The ship with a black chimney leaves at eight.
  14. The ship carrying corn is anchored next to the ship carrying rice.
  15. The ship to Hamburg leaves at six.

Aaaand one last one:

Five friends have their gardens next to one another, where they grow three kinds of crops: fruits (apple, pear, nut, cherry), vegetables (carrot, parsley, gourd, onion) and flowers (aster, rose, tulip, lily).

  1. They grow 12 different varieties.
  2. Everybody grows exactly 4 different varieties
  3. Each variety is at least in one garden.
  4. Only one variety is in 4 gardens.
  5. Only in one garden are all 3 kinds of crops.
  6. Only in one garden are all 4 varieties of one kind of crops.
  7. Pears are only in the two border gardens.
  8. Paul's garden is in the middle with no lily.
  9. Aster grower doesn't grow vegetables.
  10. Rose grower doesn't grow parsley.
  11. Nuts grower has also gourd and parsley.
  12. In the first garden are apples and cherries.
  13. Only in two gardens are cherries.
  14. Sam has onions and cherries.
  15. Luke grows exactly two kinds of fruit.
  16. Tulips are only in two gardens.
  17. Apples are in a single garden.
  18. Only in one garden next to the Zick's is parsley.
  19. Sam's garden is not on the border.
  20. Hank grows neither vegetables nor asters.
  21. Paul has exactly three kinds of vegetable.

Who has which garden and what is grown where?

So who has the answer to all of these?