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

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Can you count the number of triangles inside a triangle?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

With the help clues provided in the image, can you find the 5 digit key?

If eleven plus two equals one, what does nine plus five equal?

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?

I can be made.
I can be cracked.
I can be told.
I can be played.

Who am I?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?