What has to be broken before you can use it?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

Spot the cat in the picture below

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

Can you make a six-letter word using the letters N, A and B ?

It was a dark stormy night and a couple were in a car driving madly to a city. The car broke down and the husband had to go get help from someone who spoke his language. He was afraid to leave his wife alone in the car so he locked the car before leaving. When he came back, the car was in the same state as he had left it but his wife was dead, there was blood on the floor and there was a stranger in the car. What happened?

Can you write down eight eights so that they add up to one thousand?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you place six X (crosses) in below board without making three in a row in any way ?