What is the centre of gravity?

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

Before Mount Everest was discovered, what was the highest mountain in the world?

who is silent in the parliament?

John was drowned by he was not wet. How?

Aman has 1.15 rupees in his pocket. There are a total of 6 coins in his pocket.

When his friend asked him for a change, he could not give change for a rupee and five paisa.

Can you tell which coins he has?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

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

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?