What is the word or phrase?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

Count the number of triangles in the below picture?

You need to remove two matchsticks to make the below equation true. Can you do it ?

What is the longest word in the dictionary?

1 rabbit saw 9 elephants while going to the river. Every elephant saw 3 monkeys going toward the river. Each monkey had 1 parrot in each hand. How many animals are going towards the river?

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

I am written with two letters.
I said with the one.
I usually am seen with the two.

Who am I?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.