What Time Should the last watch show in the below figure?

Count the number of triangles in the picture below:

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

who is silent in the parliament?

In the picture given below, can you find out which digit will take place of the question mark?

Can it be possible to build a house that has all its four walls facing towards the South?

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

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?