Top 10 Logic Puzzles

So you think you are clever, right? Then here is your chance to pit your brain against some of the world’s hardest logic puzzles ever created.

1. 10 identical bottles of pills

We have 10 identical bottles of identical pills (each bottle contain hundred of pills). Out of 10 bottles 9 have 1 gram of pills but 1 bottle has pills of weight of 1.1 gram. Given a measurement scale, how would you find the heavy bottle? You can use the scale only once.

2. Camel and Banana Puzzle

The owner of a banana plantation has a camel. He wants to transport his 3000 bananas to the market, which is located after the desert. The distance between his banana plantation and the market is about 1000 kilometer. So he decided to take his camel to carry the bananas. The camel can carry at the maximum of 1000 bananas at a time, and it eats one banana for every kilometer it travels.

What is the most bananas you can bring over to your destination?

3. Measure 4 gallon of water from 3 gallon and 5 gallon water

How to measure exactly 4 gallon of water from 3 gallon and 5 gallon jars, Given, you have unlimited water supply from a running tap.

4. Pirates and 100 Gold Coins Puzzle

There are 5 pirates in a ship. Pirates have hierarchy C1, C2, C3, C4 and C5.C1 designation is the highest and C5 is the lowest. These pirates have three characteristics : a. Every pirate is so greedy that he can even take lives to make more money. b. Every pirate desperately wants to stay alive. c. They are all very intelligent.There are total 100 gold coins on the ship. The person with the highest designation on the deck is expected to make the distribution. If the majority on the deck does not agree to the distribution proposed, the highest designation pirate will be thrown out of the ship (or simply killed). The first priority of the pirates is to stay alive and second to maximize the gold they get. Pirate 5 devises a plan which he knows will be accepted for sure and will maximize his gold. What is his plan?

5. 2 Player and N Coin Puzzle

There are n coins in a line. (Assume n is even). Two players take turns to take a coin from one of the ends of the line until there are no more coins left. The player with the larger amount of money wins.

Would you rather go first or second? Does it matter?

Assume that you go first, describe an algorithm to compute the maximum amount of money you can win.

6. Secret Mail Problem

A wants to send a secret message to his friend B in the mail.
But C (A’s Friend), who A don’t trust, has access to all A’s mail. So A put his message in a box with a lock. But A is not allowed to send a key!

How can A send his message through securely?

7. Riding Against the Wind Puzzle

A horse rider went a mile in 5 minutes with the wind and returned in 7 minutes against the wind. How fast could he ride a mile if there was no wind?

8. Gold Bar Puzzle

You’ve got someone working for you for seven days and a gold bar to pay him. The gold bar is segmented into seven connected pieces. You must give them a piece of gold at the end of every day. What and where are the fewest number of cuts to the bar of gold that will allow you to pay him 1/7th each day?

9. 2 Eggs 100 Floors Puzzle

You are given 2 eggs. You have access to a 100 storey building. Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100 th floor.Both eggs are identical. You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking.
Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process.

10. Grandma and Cake Puzzle

You are on your way to visit your Grandma, who lives at the end of the valley. It’s her anniversary, and you want to give her the cakes you’ve made. Between your house and her house, you have to cross 5 bridges, and as it goes in the land of make believe, there is a troll under every bridge! Each troll, quite rightly, insists that you pay a troll toll. Before you can cross their bridge, you have to give them half of the cakes you are carrying, but as they are kind trolls, they each give you back a single cake.

How many cakes do you have to leave home with to make sure that you arrive at Grandma’s with exactly 2 cakes?

0 Thoughts on “Top 10 Logic Puzzles

  1. PALANI on July 17, 2016 at 7:46 pm said:

    Take one pill from first bottle, 2 from second 3 from third and so on. If the weight is 55.1 its first bottle …

    • Gauntlet on July 22, 2016 at 3:10 pm said:

      10. Start backwards. You have 2 cakes after the 5th troll, it gave you one back after taking half, so 2*(2-1)=2 is the number of cakes you had before crossing the 5th bridge. The same thing will happen at every bridge thus you only have to bake 2 cakes as each troll will take 1 and promptly return it.

    • Utsav Pathak on February 6, 2017 at 9:39 pm said:

      Place all the bottles on the scale than one by one start removing the bottles and if the change in value of scale is 1.1 then it will be your answer

    • Utsav Pathak on February 6, 2017 at 9:41 pm said:

      Q-1 Place all the bottles on the scale than one by one start removing the bottles and if the change in value of scale is 1.1 then it will be your answer

  2. SasiRam on July 19, 2016 at 2:39 pm said:

    Q3. Fill 5 gallon jar with water and pour water into 3 gallon jar. 2 gallon of water will be available in 5 gallon. Now empty the water in 3 gallon jar and filled it by 2 gallon of water remained in 5 gallon. Then fill 5 gallon jar and pour water into 3 gallon jar, it will take 1 gallon to fill exactly, so the remaining 4 gallon will be in 5 gallon jar.

  3. First take water in 5 gallon jar and pour in some vessel.then again take water in 5 gallon jar and pour in to remove water with 3 gallon jar 2,times from the vessel .as there is already 10 gln water in the vessel ,after removing 6 glns( 2 times with 3gains) 4 gallons will be remaing

  4. first one is simple. take the scale place it over a bottle such that its equally balanced like weighing plane. then put 2 pill from each bottle on either end. which ever side bends that pill is heavier n so is the bottle :) :P

  5. srija Ekka on April 11, 2017 at 11:46 pm said:


  6. Prateek on July 13, 2017 at 4:32 am said:

    Ans 2….532 banana maximum

  7. Patrick Wooldridge on August 12, 2017 at 9:28 pm said:

    The first puzzle should be restated for clarity (current proposition has several ambiguities). E.g.,
    You have 10 bottles of pills, each containing one hundred pills. All the bottles look exactly the same and all the pills look exactly the same. Nine of the bottles contain pills weighing 1 gram each while 1 bottle has pills weighing 1.1 gram apiece. You have a measurement scale accurate to tenths of a gram, but you may use it only once. How can you find the bottle with the heavier pills?

  8. 500 banana
    1. Take 1000 upto 250 km and leave 500 banana there and return with 250 banana up to initial position.
    2. Take another 1000 banana upto 500 km and leave 250 banana there and return back 250 km with 250

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