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

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

What is Luis Suarez's (Soccer Player) favorite tea?

A thief enters a store and threatens the clerk, forcing her to open the safe. The clerk says, “The code for the safe is different every day, and if you hurt me you’ll never get the code.” But the thief manages to guess the code on his own. How did he do it?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

A B C D E F G H

These are the letters given to you. Now you have to find out the letter that comes two to the right of the letter which is immediately to the left of the letter that comes three to the right of the letter that comes midway between the letter two to the left of the letter C and the letter immediately to the right of the letter F.

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

Can anyone tell me a word in the English dictionary which has a silent 'z'?