I am white when I am dirty, and black when I am clean. What am I?

Sharpest vision can find the lamp in the desert. Are you one of them? Test your observation skills now!

Can you solve this picture maths equation?

Which organisation is a specialized agency of the UN that deals with global health issues?

a) World Trade Organization (WTO)
b) World Health Organization (WHO)
c) International Monetary Fund (IMF)
d) United Nations Educational, Scientific and Cultural Organization (UNESCO)

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.

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

If eleven plus two equals one, what does nine plus five equal?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?