What is the next number in this matchsticks series riddle?

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?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

When monkey rotate the gear, which mark will be hit 1 or 2 ?

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

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?

Why did Navjot Singh Sidhu put the new January calendar in the freezer

What word is identified by the below rebus?

Your Your Your Your Your
Your Your Your Your Your

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?