A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Steffi's daughter Jazelle needs to be picked up from school every day.
Steffi asks one of her colleagues to pick up Jazelle from the school. Steffi devised a password system to confirm that Jazelle goes with the correct colleague only.

The password on Monday was SJM16.
The password on Wednesday was TAW39.

What will the password be for Friday?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Which word does the below Plexor means ?

John and Jacob are twin brothers. 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 John lie?' The person replied with a yes.

Whom did I talk with, John or Jacob?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

There was a minor accident with a doctor's son but the doctor noticed no major injury. After the treatment, the father of that doctors son is sitting with the son of the doctor without the doctor being in the room.

How can this be possible?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?