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?

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

which number am I?

Move four matchsticks to the below square to form three squares?

If Rajina's daughter is my daughter's mom, who am I to Rajina?

Count the squares in the matchstick puzzle below?

What number do you get when you multiply all of the numbers on a telephone's number pad?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

How can I get the answer 24 by only using the numbers 8,8,3,3?

You can use the main signs add, subtract multiply and divide.

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

The centre of the third figure is empty. What digit should fit inside?