Curve in a Box
Is it possible to design a simple closed curve inside a box, such that its projections on all 6 walls of the box are trees, i.e. curves without loops?
SOLUTION
Yes, it is possible, as shown on the image below.
Category: Insight
Puzzle Prime is tirelessly looking all around the internet to find the very best puzzles and bring them all to puzzleprime.com.
Erica, Tina, and Mark
If Erica lives in New York and Tina lives in Buenos Aires, where does Mark live?
SOLUTION
New York is the largest city in the United States of Am-Erica. Buenos Aires is the largest city of Argen-Tina. Therefore Mark lives in Den-Mark’s largest city – Copenhagen.
Abbreviations
Can you find what the following abbreviations stand for?
24 H in a D = 24 Hours in a Day
26 L of the A = ???
7 D of the W = ???
7 W of the W = ???
12 S of the Z = ???
66 B of the B = ???
52 C in a P (W J) = ???
13 S in the U S F = ???
18 H on a G C = ???
39 B of the O T = ???
5 T on a F = ???
90 D in a R A = ???
3 B M (S H T R) = ???
32 is the T in D F at which W F = ???
15 P in a R T = ???
3 W on a T = ???
100 C in a R = ???
11 P in a F (S) T = ???
12 M in a Y = ???
13 is U F S = ???
8 T on a O = ???
29 D in F in a L Y = ???
27 B in the N T = ???
365 D in a Y = ???
13 L in a B D = ???
52 W in a Y = ???
9 L of a C = ???
60 M in a H = ???
23 P of C in the H B = ???
64 S on a C B = ???
9 P in S A = ???
6 B to an O in C = ???
1000 Y in a M = ???
15 M on a D M C = ???
SOLUTION
24 H in a D = 24 Hours in a Day
26 L of the A = 26 Letters of the Alphabet
7 D of the W = 7 Days of the Week
7 W of the W = 7 Wonders of the World
12 S of the Z = 12 Signs of the Zodiac
66 B of the B = 66 Books of the Bible
52 C in a P (W J) = 52 Cards in a Pack (Without Jokers)
13 S in the U S F = 13 Stripes in the United States Flag
18 H on a G C = 18 Holes on a Golf Course
39 B of the O T = 39 Books of the Old Testament
5 T on a F = 5 Toes on a Foot
90 D in a R A = 90 Degrees in a Right Angle
3 B M (S H T R) = 3 Blind Mice (See How They Run)
32 is the T in D F at which W F = 32 Degrees is the Temperature in Fahrenheit at which Water Freezes
15 P in a R T = 15 Players in a Rugby Team
3 W on a T = 3 Wheels on a Tricycle
100 C in a R = 100 Cents in a Rand
11 P in a F (S) T = 11 Players in a Football (Soccer) Team
12 M in a Y = 12 Months in a Year
13 is U F S = 13 is Unlucky For Some
8 T on an O = 8 Tentacles on an Octopus
29 D in F in a L Y = 29 Days in February in a Leap Year
27 B in the N T = 27 Books in the New Testament
365 D in a Y = 365 Days in a Year
13 L in a B D = 13 Loaves in a Baker’s Dozen
52 W in a Y = 52 Weeks in a Year
9 L of a C = 9 Lives of a Cat
60 M in an H = 60 Minutes in an Hour
23 P of C in the H B = 23 Pairs of Chromosomes in the Human Body
64 S on a C B = 64 Squares on a Chess Board
9 P in S A = 9 Provinces in South Africa
6 B to an O in C = 6 Balls to an Over in Cricket
1000 Y in a M = 1000 Years in a Millennium
15 M on a D M C = 15 Men on a Dead Man’s Chest
Professor Al’s Books
Professor Al has put the “Lord of the Rings” trilogy books on his shelf in order, next to each other. The books are hard copies, with pages which are 1/100in thick and covers which are 1/8in thick. A worm is eating its way from the first page of the first volume to the last page of the third volume. If each of the volumes contains 400 pages, how long this distance is?
SOLUTION
The first page of the first volume and the last page of the third volume are separated only by the second volume and the extra 2 book covers. Therefore the distance is 4in + 0.5in = 4.5 inches long.
Getting Older
If the day before yesterday Tim was 18 years old and next year he will be 21 years old, what is the date today?
SOLUTION
Today is 1st of January.
Every Song
John: “I know every song in the World.”
Paul: “It can’t be. I bet you don’t know any songs which contain the name of my daughter – Beatrice.”
John accepted the bet and won. Which song did he sing?
SOLUTION
John performed the “Happy Birthday” song.
Place a Coin
Two friends are playing the following game – taking turns, they place identical coins on a square table, so that no two coins touch each other. Whoever can not make a move, loses the game. Who has a winning strategy?
SOLUTION
The first player has a winning strategy. He just has to place the first coin in the center of the table and then each consecutive one symmetrically opposite to the last coin of his opponent.
Beat Strata
Strata is a beautiful award-winning game with mesmerizing sound and unique puzzle concept. It contains hundreds of levels with common rules and final goal. Below I present you these rules and ask you to find a universal algorithm, which will allow you to solve easily every single level of the game.
The rules are simple – you begin with an nxn board, some squares of which are colored in arbitrary colors. Then you start placing stripes of whatever color you choose over entire rows and columns of the board. Your task is after placing all available 2n stripes, the color of every (colored) square to match the color of the stripe which has been placed second over it (on top).
Can you find a simple algorithm, which results in solving any level of the game, no matter the starting position? You can watch AppSpy’s video below for better understanding of the rules.
SOLUTION
Imagine the reverse Strata puzzle – the color of every square must match the color of the first stripe which is placed upon it. Clearly, there must be a line in the grid such that all colored squares in it have the same color. Take all such lines in the grid and place on them stripes of appropriate colors. Then erase the colors from all squares covered by the stripes and repeat the procedure until you place all 2n stripes. It is easy to see that if the reverse Strata puzzle has a solution, then we will find it using this strategy. Finally, in order to solve the original Strata puzzle, just place the stripes in reverse order.
The Rotating Square
On the table in front of you there is a square with 4 coins placed on its vertices. You are blindfolded and are given the task to turn all of the coins with either heads up or tails up. Every time you turn few of the coins however, the square rotates arbitrarily on the table. Find a strategy, such that no matter the starting arrangement of the coins and no matter how the square rotates after every flip of coins, eventually you will turn all of the coins with the same face up.
SOLUTION
First assume that there is even number of tails and even number of heads on the table – 2 of each kind. Flip 2 opposite coins. If after that not all coins have the same face up, the coins’ faces along the square’s corners show T-T-H-H. Now flip 2 adjacent coins. If after that not all coins have the same face up, the coins’ faces along the square’s corners show T-H-T-H. Now flip again 2 opposite coins and you are done.
Next assume that there were intially odd number of tails and odd number of heads on the table. Then after applying the moves described above, flip one of the coins upside down. Now there is even number of heads and even number of tails on the table, so you can repeat the same procedure and accomplish the task.
Ball Thrower
How can you throw a ball and have it come back to you, even though the ball is not attached to anything, doesn’t bounce off anything and nobody catches it and throws it back to you?
SOLUTION
Throw it straight up in the air.