Replace the question mark with the number below given a simple math problem.

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

Can you write down eight eights so that they add up to one thousand?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

In the below-given picture of a pretty girl, there is something wrong. Can you find out what it is?

Wednesday, Steve and Pam go to a restaurant to eat lunch. After eating lunch, they pay the bill. But Steve and Pam do not pay the bill. So…who does?

A man was telling some of his war stories to his grandchildren.
"When the World War I was on the verge of end, I was awarded for my bravery for I had saved a group of my men." He coughed and then added, "When we were fighting in northern France, an enemy soldier threw a grenade at us. Before it could explode, I picked it up and threw it away. For my act of bravery, right before the war ended, A General gave me a sword engraved with the words "Awarded for Display of Bravery and Heroism in World War 1"."

Hearing this, one of the grandson spoke up. "Grandpa, this is not a true story. It can"t be true!"

The truth is that it was not. How did the grand children know it?