#361 - Maths Logical Problem

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

Maths Logical Problem

Let us consider the length of the tunnel first; which is 200 miles. Now, the trains are running on the same speed which means that they will collide at the center of the tunnel and will take an hour to reach the center. Now the bird is travelling at a speed of 1000 mph and it is flying for an hour (since the trains will take an hour to collide). Thus the bird will travel 1000 miles in the process.

#362 - Truth Lie Puzzle

Tia and Mia are twin sisters.One of them is a liar whereas the other one is a truth teller.

I called their home number and one of them picked up.
I asked. 'Does Tia lie?' The person replied with a yes.

Whom did I talk with? Tia or Mia ?

Truth Lie Puzzle

I spoke with Mia.

Let us assume that Tia is a liar and Mia is a truth teller.
If I asked the question from Mia, the answer will be yes. If I asked the question from Tia, the answer will be no. Thus I must have asked from Mia.

Let us assume that Tia is a truth teller and Mia is a liar.
If I asked the question from Mia, the answer will be yes. If I asked from Tia, the answer will be no. Thus in this case as well, I must have asked from Mia.

#363 - Hard Count Number Triangles Puzzle

Can you count the number of triangles on the puzzle below.

Hard Count Number Triangles Puzzle

64

#364 - Tough Probability Interview Question

There is a country where everyone wants a boy. Every family continue to have babies till a boy is born. If the probability of having a girl or a boy is the same, what is the proportion of boys to girls after some time in that country?

Tough Probability Interview Question

Since the probability of having a girl or a boy is same, half of the families will have a boy first and stop. The other half of the families will have a girl and from half of those families, the second born will be a boy and they will stop while the others will again have a girl. This process will continue.

Suppose the number of couples are N, the number of boys will be N.

1/2 have a boy and stop: 0 girls
1/4 have a girl, then a boy: N/4 girls
1/8 have 2 girls, then a boy: 2*N/8 girls
1/16 have 3 girls, then a boy: 3*N/16 girls
1/32 have 4 girls, then a boy: 4*N/32 girls
…
Total: N boys and
1N 2N 3N 4N
– + – + – + — +… = ~N

Therefore the proportion of boys to girl will be quite close to 1:1.

#365 - Short History Riddle

October Revolution is well know in russian history. Which month do they celebrate it ?

Short History Riddle

November, Their calandar was 13 days behind ours.

#366 - Tricky Math Logic Problem

A girl was fond of collecting rare stamps. When she was twenty years old, she bought a box to collect her stamps. On her every birthday, she put 250 stamps in it and her sister who was also fond of collecting stamps took out 50 stamps from it on her birthday. The girl met an accident when she was 60 years old. When her box was opened, there were only 500 stamps in it.

How is it possible logically?

Tricky Math Logic Problem

The girl was born on 29 February, thus she put 250 stamps every four years.
In forty years, she put stamps only 10 times which makes the total of 2500 stamps.
Her sister was born on any other day and she took out 50 stamps from the box forty times which makes the total stamp she took out to be 2000.

Thus after forty years, the girl’s box had only 500 stamps.

#367 - Hard Math Sequence Puzzle

Find the next number in the sequence ?

2 3 3 5 5 4 7 5 11 6

Hard Math Sequence Puzzle

13 8 its prime number and then number of letter in prime number

#368 - 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

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.

#369 - 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

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

#370 - 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

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