I taste better than I can smell. Who am I?

Can you count the number of squares in the figure below?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

How many letters are in the alphabet?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

A donkey is behind another donkey
I'm behind that second donkey
But there is a whole nation behind me

It is a murder you can describe in a word.