Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

Why did the Girl throw the butter out of the window?

My location can be determined by the below rebus.
So where am i ?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

I am not a bull but I have horns.
I am not an ass but I have a pack saddle.
Wherever I go, I leave silver behind me.

Who am I?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

Dr Doom invited a group of puzzle fanatics to a party which was oriented toward having puzzle-oriented games. At night, he introduced the guests to a 'unique riddle'. A prize was offered to the one who solved it first.

The guests included six people named Tom Paul, Fox Obama, Jeremy Reener, Alex Murphy, Prim Pastor, and Ellen Page. The winner of the 'unique riddle' contest was to be announced after the dinner. So Dr. Doom stood up and started the announcement:

'Okay now everybody!'
'The winner of�'
'The Hardest Riddle Ever Event'

But before he could complete it, the light went out and his voice was not heard without the mic by anyone. But they already knew who the winner was. Can you deduce the name of the winner?

Find the missing number in the sequence below: