Why Wine Glass Stem is so long?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

Remove two matchsticks to make the below equation correct.

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

The cream is heavier than Milk. True or False?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?