If 21x = 79x, what is the value of x?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

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

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

Twenty frogs are sitting on a log floating on the surface of a river. Two of them decide to jump off into the water.

How many frogs are there on the log at this moment?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

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

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?