What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Rob is taller than Edwin, and Jurgen is shorter than Rob.
Of only one of the following statements, we now certainly know it is correct:

A.Edwin is taller than Jurgen
B.Jurgen is taller than Edwin
C.It cannot be determined if Jurgen or Edwin is the tallest.

Can you solve the below tricky visual equation?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Two friends Smith and Andrew were talking about the bravery of their families. Smith told great stories about his courageous grandfather who fought for Britain in "World War I". Andrew told that his grandfather was so brave that in 1919 just after the war he was honoured with a bravery medal with the words "For our Courageous Soldiers In World War I" embedded into it. Smith knows that his friend is lying. How?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?