IN A STREET THERE ARE FIVE HOUSES PAINTED FIVE DIFFERENT COLOURS IN EACH HOUSE LIVES A PERSON OF DIFFERENT NATIONALITY THESE FIVE HOME OWNERS EACH DRINK A DIFFERENT KIND OF BEVERAGE SMOKE DIFFERENT BRAND OF CIGAR AND KEEP A DIFFERENT PET THE BRITISH MAN LIVES IN A RED HOUSE THE SWEDISH MAN KEEPS DOGS AS PETS THE DANISH MAN DRINKS TEA THE RIDDLES WITH ANSWERS TO SOLVE - PUZZLES & BRAIN TEASERS

The cemetery Did you answer this riddle correctly?
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His father was in front of him when he was born, therefore he was born before him. His mother died while giving birth to him. Finally, he grew up to be a minister and married his sister at her ceremony. Did you answer this riddle correctly?
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Peter Did you answer this riddle correctly?
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A dog. Did you answer this riddle correctly?
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Penal-Tea Did you answer this riddle correctly?
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Penal-tea. Did you answer this riddle correctly?
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Cat Did you answer this riddle correctly?
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Blood, he's a vampire! Did you answer this riddle correctly?
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Gravi-tea. Did you answer this riddle correctly?
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The third equation has a term with a pair of whistles. The last line involves a single whistle.

Furthermore, the man in the second and third lines are wearing a whistle, but the man in the last line is not wearing a whistle. Presumably the value of the whistle should be accounted for to get the correct answer.

The pictures can be translated into the following equations:

shoes + shoes + shoes = 30
shoes + (man + whistle) + (man + whistle) = 20
(man + whistle) + 2(whistles) + 2(whistles) = 13
shoes + (man) x (whistle) = ?

From the first equation we can solve for the shoes value:

shoes + shoes + shoes = 30
3(shoes) = 30
shoes = 10

We can then solve the second equation for the (man + whistle) value:

shoes + (man + whistle) + (man + whistle) = 20
10 + 2(man + whistle) = 20
2(man + whistle) = 10
man + whistle = 5

Then we solve the third equation for the whistle:

(man + whistle) + 2(whistles) + 2(whistles) = 13
5 + 4(whistles) = 13
4(whistles) = 8
whistle = 2

We also need to solve for the value of the man:

man + whistle = 5
man + 2 = 5
man = 3

Now we can evaluate the final expression, remembering the order of operations that multiplication should be evaluated before addition:

shoes + (man) x (whistle) = ?

10 + 3 x 2
= 10 + 3 x 2
= 10 + 6
= 16 Did you answer this riddle correctly?
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The President. Did you answer this riddle correctly?
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A boat. Did you answer this riddle correctly?
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On the world wide web. Did you answer this riddle correctly?
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There are no stairs in a one story house. Did you answer this riddle correctly?
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So they could hide in the tomatoes. Did you answer this riddle correctly?
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