Can you find the missing piece of the Porsche?

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?

Can you tell a 3D object that has just two surfaces?

I am the largest in my family of fifty.
The youngest of our family lives separately from the rest of the family and so do I.
I am regarded as harsh and tough.
I am so large, you cut me in two equal halves,
each half would still be larger than the second largest member of the family.
Who am I?

I have an apple tree , number of apple in this tree get doubles every week.

On 30th week , the tree gets completely filled with apples :-)



Can you tell me , on what week does my tree is half covered with apples ?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

Can you count the number of lines in the below picture?

Keyboard words are not in alphabetical order, Why?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

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

Who am I?