How can you write nineteen in a manner that if we take out one, it becomes twenty?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

If a wheel has 54 spokes, how many spaces are there between the spokes?

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

Replace the question mark with the correct number in the below-given picture?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What is the centre of gravity?

Find the Odd One Out?
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