#361 - Hard River Crossing Logic Puzzle

You must have heard of so many river crossing riddles however this one is a bit tricky one. We have a dysfunctional family on one side of the river which includes mom and 2 daughters, dad and 2 sons, a maid and a dog. Like usual, there is a boat that can hold only two persons at a time (dog counts as one person as well). Obviously, the kids can’t operate the boat and we need an adult for that task.

Here comes the difficulties. The maid must remain with the dog so she can control it or it will head up for a violent biting. The dad cannot be left with the daughters without mom and nor can the mother be left alone with the sons without dad.

Can you help them cross the river?

Hard River Crossing Logic Puzzle
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Suppose that everyone is standing at A corner and they have to reach the B corner

Let the housemaid and Dog go to corner B first and housemaid returns back to corner A.

Next, the housemaid and the first son go to B and she comes back along with the dog.

Now the father and the second son go to B and father comes back.

Mother and Father go to B and the mother comes back.

Housemaid and Dog go to B and the father comes back.

Father and mother goes to B and Mother returns back.

Mother and first daughter go towards B, Housemaid and Daughter returns back.

Housemaid and second Daughter go to B and Housemaid comes back.

Housemaid and Dog goes to B.

So, everyone has reached the other side of the river successfully.

#362 - Trickiest Primates Riddle

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room ?

Trickiest Primates Riddle
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You are also a primate and you are human thus you are the most intelligent.

#363 - Trick Logic Riddle

Alex is asked to stand behind Ryan and Ryan is asked to stand behind Alex. Both of them feel confused about it and don’t know what to do?

But it is quite possible, do you know how?

Trick Logic Riddle
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If Alex and Ryan stand back to back, then they can make it possible.

#364 - Counting Chess Squares Puzzle

How many squares are there in a chess board ?

Counting Chess Squares Puzzle
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204

#365 - Famous Trivia Puzzle

Can you tell a 3D object that actually has just two surfaces?

Famous Trivia Puzzle
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Did you think of paper?
Well that will be a wrong answer as a piece of paper has 6 surfaces as the edges are also counted as surfaces only no matter how thin they are.

The correct answer is a cone.

#366 - Clever Logic Riddle

A dying old man wants to divide his entire land between his only two sons. Since his only wish is to treat them as equal as both of them have been too good to him, he wants to divide his land equally between them. The problem is that the land is significantly irregular in shape and thus there is no choice of cutting them in two equal halves.

Can you help him divide the land in a manner that both of his sons will be happy ?

Clever Logic Riddle
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All he need to do is ask one of his son to divide the land in two part and tell him that the other son will have the choice of selecting one of those two halves.

In this manner both of them will be happy.

#367 - Trivia Science Riddle

If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

Trivia Science Riddle
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The most common answer would be 5. But that’s totally incorrect. It will be the square root of 10 times stronger i.e. 3.16 times.

#368 - Hard Logic Amazon Interview Puzzle

Two friends were stuck in a cottage. They had nothing to do and thus they started playing cards. Suddenly the power went off and Friend 1 inverted the position of 15 cards in the normal deck of 52 cards and shuffled it. Now he asked Friend 2 to divide the cards into two piles (need not be equal) with equal number of cards facing up. The room was quite dark and Friend 2 could not see the cards. He thinks for a while and then divides the cards in two piles.

On checking, the count of cards facing up is same in both the piles. How could Friend 2 have done it ?

Hard Logic Amazon Interview Puzzle
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Friend 2 must have taken top 15 cards from the pile and reversed them. Now there are two piles, one with 15 cards and one with 37 cards and both of them will obviously have the same number of inverted cards.

If you want to understand mathematically, let us say that there were x inverted cards in the top 15 cards of the deck. Then the remaining 37 cards will comprise of 15-x number of inverted cards.

If we reverse the 15 cards the number of inverted cards will become 15-x and the number of inverted cards will be same in both the piles.

#369 - Inmobi Interview Bottle Puzzle

There are two bottles that consists of different pills each. You must take the two pills at the same time and if you forget, or just take one of them or take two of the same kind, you will die a miserable death. In a hurry, you pour from both the bottles at the same time and three pills fall down in your hand.

Now you can’t throw away the pills as they are quite rare to be found. Also both of the pills look exactly the same and have all the characteristics similar. How will you ensure that you don’t take a wrong pill and die ?

Inmobi Interview Bottle Puzzle
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All you have to do is labelling the pills as A and B. Now when you draw out three pills, you will either have 3A or 2A 1B or 1A 2B or 3B. Now if all the pills are from same bottle you can simply take another from the other bottle. If some other combination comes out, you can manage by filling in from the required bottles.

#370 - Hard Number Riddle

Can you find out the smallest number that can be conveyed as the sum of three squares in three unique ways ?

Hard Number Riddle
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54
7^2 + 2^2 + 1^1
6^2 + 3^2 + 3^2
2^2 + 5^2 + 5^2