Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

What has hands, but can’t clap?

Three logicians went to bar for having a drink. The bar person asks the logicians "Do they all want to have the drink?". The first logician replied, " I don't know". The second logician replied, " I don't know". What is the reply of the last logician?

Can you decipher the below rebus?

PBLUESAISNUERSES

What does this rebus mean?

O
N
C
E
TIME

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

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

John was drowned by he was not wet. How?

The teacher told the student that if he told a lie then he will be expelled from school and if he told the truth then he still is expelled from school.

What can a student say to prevent his being expelled from school?