what it is?

below shown is the sketch of a German Submarine

this is famous Eiffel Tower

this is a bridge made up of iron and steel

Now can you tell what it is?

most of the buildings are, nowadays, constructed using concrete bricks. earlier clay bricks used but availability of clay is bit hard.

manufacturing process:

the big rocks from mountain is crushed into small size in a crusher. It is then transported to the work site. there it is mixed with sand and cement to make concrete. this is done in an concrete-mixture-machine. then it is shaped into brick with help of an electric power press.

if we analyze the manufacturing process, we can see that lot of energy spent in all the way.

move the die

shown below is a die on the corner of the square board of 3x3 grid board. you are allowed to roll the die, a quarter turn over a bottom edge so that it moves to an adjacent square.
diagonal movement is not allowed.
any path you can choose.
what number of spots, when the die is resting on the square in the position indicated by dotted line , never appears on the top face of the die?

The clue : total of spots on the two opposite faces is SEVEN

shortest path

A geometrical shape is made up of 14 rectangles each having a size of 6cm x 2 cm. Two paths are shown in RED and BLUE color through the edges of rectangles. out of these two paths which is the shortest path and what is the length of that path

The Oxford murders

a  series of symbols is given  above . what is the fourth symbol in this series? it is a puzzle asked by the Prof. Arthur seldom at the Oxford University. don't expect the answer here. if you want to know the forth symbol and also about Prof. Arthur Seldom, watch the movie "The Oxford Murders" released in 2008.

in this movie, an Oxford university professor and grad student trying to stop a series of murders linked with mathematical symbols.