The Number in the Yellow Circle
Which is the missing number in the yellow circle?
SOLUTION
The missing number is 12. Each number is the sum of the digits of the numbers pointing towards it.
Tag: Advanced
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Vinculus Puzzles
Circles are particles and lines joining them are bonds. The objective is to find all the hidden values, following these four rules:
- Particle values must be the sum of their bond values.
- Particles can have the following values: 0, 1, 2, 4, 8, 12, 16.
- Bonds can have the following values: 0, 1, 2, 4.
- If two particles have the same value, the bond between them must have value 0.
EASY MEDIUM HARD
SOLUTION
The solutions are shown below.
Five Men in the Rain
There were five men going to church and it started to rain. The four that ran got wet and the one that stood still stayed dry.
SOLUTION
Four of the men were carrying a dead man in a coffin to his funeral.
What is the next number in this sequence?
What is the next number in this sequence?
4, 2, 3, 4, 6, 2, 4, ?
SOLUTION
The answer is 8. The numbers represent the lengths of the words in the question:
what → 4
is → 2
the → 3
next → 4
number → 6
in → 2
this → 4
sequence → 8
Canals on Mars Maze
Starting with the letter “T” at the bottom, visit all spots exactly once before returning to the beginning, so that the letters you pass through spell a complete sentence.
SOLUTION
The path goes through the letters “T”, “H”, “E”, “R”, “E”, “I”, “S”, “N”, “O”, “P”, “O”, “S”, “S”, “I”, “B”, “L”, “E”, “W”, “A”, “Y”, to spell the sentence “There is no possible way”.
Canaries in Space
NASA was considering sending canaries into space to study them under zero gravity. The project was scrapped when someone realized that in spite of having sufficient water supplies, they could die of dehydration within a few hours. Why?
SOLUTION
Unlike humans, birds need gravity in order to swallow. Thus, in space they wouldn’t be able to drink and will die of dehydration.
53 Bicycles and a Dead Man
There is a room with a table, 53 bicycles, and four men. One of the four men is dead. How did he die?
SOLUTION
The “bicycles” are the (famous) Bicycle playing cards. The four men were playing poker, but one of them was cheating with an extra card, so he got killed.
Raise Me None
Raise me none and I am unbeaten.
Raise me once and I am excessive.
Raise me twice and I am forward.
Raise me thrice and I am eaten.
All said right, but wrongly spelled.
Who am I?
SOLUTION
The answer is the NUMBER 2:
2⁰ = 1 (“one”), which is unbeaten;
2¹ = 2 (“too”), which is excessive;
2² = 4 (“fore”), which is forward;
2³ = 8 (“ate”), which is eaten.
Envelopes with Numbers
You are given 2 sealed envelopes with numbers inside. You are told that one of the numbers is twice as much as the other one. You grab one of the envelopes and right before you open it, you make the following calculation:
“If this envelope contains X inside, then the other envelope contains either X/2 or 2X inside. Since the chance that the other envelope contains a larger number is exactly 50%, the expected money I will get after switching is X/4 + X = 1.25X > X. Therefore, I should switch!”
Clearly, this reasoning is wrong, since you can’t possibly deduce which envelope of the two contains a larger number. Where is the mistake?
SOLUTION
The trick is that conditionally on the fact that your envelope contains X, it is not true that the other envelope has 50% chance of containing either X/2 or 2X. The reason is that it is impossible that all amounts of dollars appear in the envelopes with the same probabilities (densities). Thus, for example, if it is very unlikely that an envelope contains more than 1000, and you open an envelope with 800 inside, you will not think that the other envelope has 50% chance of containing 1600.