What is so fragile that saying its name breaks it?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

Count the Triangle in the figure given below:

Can you find out who is the kidnapper in below Picture and why, Explain ?

A thief is convicted in Mexico. He gets the death penalty. The judge allows him to say the last sentence to determine how the penalty will be carried out. If the thief lies, he will be hanged, if he speaks the truth he will be beheaded. The thief tells the last sentence and to everybody's surprise some minutes later he is set free because the judge cannot determine his penalty. What did the thief say?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

Name a key which is hardest to turn.

What has 13 hearts but no other organs?

Teacher ask the student

'Why are you standing on that chair in music class ?'.

what did student replied ?