# Solve This! The Sliding Puzzle Quiz

By: John Kelly

Image: Science Picture Co/Collection Mix:Subjects/Getty Images

They're addictive, engrossing and maddening. Sliders have been around for well over a century, but you still may have a lot to learn about these braintwisters.
What is the first sliding puzzle commonly known as?
Rubik's Slider
The 15 Puzzle
It took its name from its 4-by-4 grid with 15 tiles and one empty space.
Tic Tac Toe

What shape were the pieces of the original sliding puzzle, the 15 Puzzle?
square
The pieces of the 15 Puzzle were all squares. Can you imagine trying to slide interlocking triangles?
triangular
circular

How many 15 Puzzle configurations are solvable?
all of them
half of them
Exactly half the possible arrangements of the numbers can be returned to numerical order with the empty square at the end.
all except one

The 15 Puzzle became popular in which year?
1880
The 15 Puzzle was a huge sensation in the early months of 1880. Though the craze died down by the summer, the 15 Puzzle is still popular today.
1980
1890

Who was the inventor of the 15 Puzzle?
Sam Loyd
Noyes Chapman
Though Sam Loyd claimed be its inventor, the 15 Puzzle was actually the creation of postmaster Noyes Chapman.
P.T. Barnum

How can sliding puzzle pieces be moved?
by jumping over another piece
by flipping them
by moving them into an empty space
Sliding puzzle pieces can only be rearranged by moving them into an empty space.

True or False: The simpler a sliding puzzle's design, the easier it is to solve.
True
False
Some very simple sliding puzzles are extremely difficult to solve.

Why was the Pennant Puzzle of 1909 harder to solve than earlier sliding puzzles?
It used rectangular pieces.
Rectangular pieces complicated the solution of the Pennant Puzzle, also known as Dad's Puzzle.
The pieces were all the same color.

True or False: Even computers have a hard time solving sliding puzzles.
True
The myriad of movement options and variables of these puzzles are so complex that they present a challenge to computers.
False

Ma's Puzzle, released in 1927, introduced what element into sliding puzzles?
T-shaped pieces
L-shaped pieces
The L-shaped pieces of Ma's Puzzle added a new degree of complexity to its solution.
Z-shaped pieces

What is the key to solving sliding puzzles?
moving two pieces at once
converting the puzzle to a mathematical formula
There is no key.
Sliding puzzles are difficult because there's no key or formula that tells you how to solve them. As with most things, patience is your best asset.

The Japanese sliding puzzle Sokoban represents what kind of worker?
taxi dispatcher
warehouse manager
Sokoban is the Japanese word for "warehouse manager." In this puzzle, the manager (player) has to move boxes into their proper position.
airline pilot

What makes Sokoban especially difficult?
Pieces can be pushed, but not pulled.
Because the boxes can only be pushed and not pulled, it's easy to reach a dead end.
The pieces are different colors.
The game has a warp factor that randomizes the tiles.

What professional group has a history of sliding puzzle analysis?
mathematicians
While philosophers and psychologists may find these diversions fascinating, the principles behind solving sliding puzzles have long intrigued mathematicians.
philosophers
psychologists

When mathematicians judge a puzzle PSPACE-complete, what does this mean?
The puzzle is complex and difficult to solve.
The term PSPACE-complete is a measure of mathematical complexity and difficulty.
The puzzle has a certain number of empty spaces.
The puzzle cannot be solved except by a computer.

What claim is made for the computer-designed puzzle called Quzzle?
It's a puzzle no one has ever solved.
It's the best puzzle for a child.
It's the most difficult simple sliding puzzle.
Quzzle's inventor claims it is the hardest simple sliding puzzle to solve.

Rubik's Cube, a relative of the sliding puzzle, created a sensation in which decade?
1880s
1960s
1980s
Rubik's Cube was all the rage during the early 1980s. A total of more than 350 million have been sold since the Cube was introduced.

How long did it take chess champion Bobby Fischer to solve Rubik's Cube?
5 minutes
2.5 minutes
25 seconds
Fischer solved the puzzle in 25 seconds on the Tonight Show.

What is the world's record for solving Rubik's Cube?
21.71 seconds
15.66 seconds
5.66 seconds
At a 2011 contest, Latvian puzzle whiz Feliks Zemdegs unscrambled the cube in 5.66 seconds to set a world's record.

Which renowned puzzle inventor has an annual puzzle design award named for him?
Feliks Zemdegs
Nob Yoshigahara
Nob Yoshigahara, who died in 2004, was one of the world's leading puzzle designers. The Nob Yoshigahara Puzzle Design Competition is held annually.
Junk Kato