How many words can a pen with half refill write?

There was a strange boy who was born before his father. How can this be possible?

Can you name an animal whose killing cannot be performed without spilling your own blood?

When can we add 2 to 11 and get 1 as the correct answer?

What word is pronounced the same if you take away four of its five letters?

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?

The dirtier I get, the whiter I look. Who am I?

What Time Should the last watch show in the below figure?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Find the next number in the series below

21 32 54 87 131 ?