Why 1729 is a magic number? Answer Logically.

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?

What is black when you buy it, red when you use it, and gray when you throw it away?

It is always ahead of me yet I can never see it. What is it?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

Whats the next number in the below number sequence pattern.

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?