What does does this rebus picture means ?

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

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?

When Jack was six years old he hammered a nail into his favourite tree to mark his height. Ten years later at age sixteen, Jack returned to see how much higher the nail was. If the tree grew by five centimetres each year, how much higher would the nail be?

O_er_t_o_

Complete the missing letters of the given word.

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

What word is represented by this rebus?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

The more it dries, the wetter it becomes. Can you tell what it is?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?