What is the word or phrase?

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 ?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

Our product and our sum always give the same answer. Who are we?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?

If you were to put a coin into an empty bottle and then insert a cork into the neck, how could you remove the coin without taking out the cork or breaking the bottle?