If you’re like me, then you love logic puzzles! Whether it’s for the thrill of solving the conundrum or just the the excitement of facing a challenge, there are plenty of reasons to enjoy these mental puzzles. I’ve found a few different puzzles online that I think you might enjoy.
There are 4 difficulty levels: very easy, easy, difficult, and very difficult. I’ll give you two puzzles from each level, but you can find more here. The links to the answers (and hints) will be at the end. See how many you can solve!
Difficulty: Very Easy
Four Tasmanian camels traveling on a very narrow ledge encounter four Tasmanian camels coming the other way.
As everyone knows, Tasmanian camels never go backwards, especially when on a precarious ledge. The camels will climb over each other, but only if there is a camel-sized space on the other side.
The camels didn’t see each other until there was only exactly one camel’s width between the two groups.
How can all camels pass, allowing both groups to go on their way, without any camel reversing?
The Double Jeopardy Doors
Difficulty: Very Easy
You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don’t know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don’t know which is which.
What is the question you ask?
You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.
How do you measure 45 minutes?
A corporate businessman has two cubes on his office desk. Every day he arranges both cubes so that the front faces show the current day of the month.
What numbers are on the faces of the cubes to allow this?
Note: You can’t represent the day “7” with a single cube with a side that says 7 on it. You have to use both cubes all the time. So the 7th day would be “07.”
The 100 Coins
There are 10 sets of 10 coins. You know how much the coins should weigh. You know all the coins in one set of ten are exactly a hundredth of an ounce off, making the entire set of ten coins a tenth of an ounce off. You also know that all the other coins weight the correct amount. You are allowed to use an extremely accurate digital weighing machine only once.
How do you determine which set of 10 coins is faulty?
100 Gold Coins
Five pirates have obtained 100 gold coins and have to divide up the loot. The pirates are all extremely intelligent, treacherous, and selfish (especially the captain).
The captain always proposes a distribution of the loot. All pirates vote on the proposal, and if half the crew or more go “Aye,” the loot is divided as proposed, as no pirate would be willing to take on the captain without superior force on their side.
If the captain fails to obtain support of at least half his crew (which includes himself), he faces a mutiny, and all pirates will turn against him and make him walk the plank. The pirates start over again with the next senior pirate as captain.
What is the maximum number of coins the captain can keep without risking his life?
The Fake Coin
Difficulty: Very Difficult
You have twelve coins. You know that one is fake. The only thing that distinguishes the fake coin from the real coins is that its weight is imperceptibly different. You have a perfectly balanced scale. The scale only tells you which side weighs more than the other side.
What is the smallest number of times you must use the scale in order to always find the fake coin?
Use only the twelve coins themselves and no others, no other weights, no cutting coins, no pencil marks on the scale. etc.
These are modern coins, so the fake coin is not necessarily lighter.
Presume the worst case scenario, and don’t hope that you will pick the right coin on the first attempt.
The Card Trick
Difficulty: Very Difficult
I ask Alex to pick any five cards out of a deck with no Jokers.
He can inspect then shuffle the deck before picking any five cards. He picks out five cards then hands them to me (Peter can’t see any of this). I look at the cards and I pick one card out and give it back to Alex. I then arrange the other four cards in a special way, and give those four cards all face down, and in a neat pile, to Peter.
Peter looks at the four cards i gave him, and says out loud which card Alex is holding (suit and number). How?
The solution uses pure logic, not sleight of hand. All Peter needs to know is the order of the cards and what is on their face, nothing more.
Before going to the solutions, comment your answers and see how many you got right!
“Very Easy” puzzles and solutions here!
“Easy” puzzles and solutions here!
“Difficult” puzzles and solutions here!
“Very Difficult” puzzles and solutions here!