What goes up but never comes down?

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

If a boy blows 18 bubbles,
Then pops 6 eats 7 and then
He pops 5 and blows 1.
How many are left?

Count the number of triangles in the below picture?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 above and below the division line in a manner that the thus formed fractions equal to 1/3.

(You can use one number only once)

You bought me for dinner but never eat me. What am I?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?

Why do people go to bed?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?