A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

100 prisoners are stuck in the prison in solitary cells. The warden of the prison got bored one day and offered them a challenge. He will put one prisoner per day, selected at random (a prisoner can be selected more than once), into a special room with a light bulb and a switch which controls the bulb. No other prisoners can see or control the light bulb. The prisoner in the special room can either turn on the bulb, turn off the bulb or do nothing. On any day, the prisoners can stop this process and say "Every prisoner has been in the special room at least once". If that happens to be true, all the prisoners will be set free. If it is false, then all the prisoners will be executed. The prisoners are given some time to discuss and figure out a solution. How do they ensure they all go free?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

What is next number in the pattern below:

131 517 192 123 ?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

You’ll find me on Mercury, Earth, Mars, Jupiter, Saturn, and Uranus. But never Neptune, or Venus. What am I?

Why is a river so rich ?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Things are just as they seem, right? Well, check again.
Can you count the number of tigers in this picture ?