Find the value of "?" in the ball picture Riddle below:

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

Prove that twice of ten is the same as twice of eleven.

What does the below rebus riddle means?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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

which number am I?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?