Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Four cars come to a four-way stop, each coming from a different direction. They can’t decide who got there first, so they all go forward at the same time. All 4 cars go, but none crash into each other. How is this possible?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

I was born in a small house and I live in it all alone. No windows and no doors have been assigned to my house. The only way I can go out is by breaking through the walls of my house.

Who am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Decode below three cipher riddles:

26 L of the A
7 D of the W
1000 Y in a M

I have eight fingers and two thumbs but I do not live. What Am I?

What is wrong in the below Picture?

What jumps when it walks and sits when it stands?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?