Solve below rebus puzzle?

What has one letter and starts with an E?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

Imagine you are in a room with no windows or doors. How will you get out?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

What makes this number unique: 8,549,176,320?

What goes up but never comes down?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?