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

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

81 x 9 = 801. What must you do to make the this equation true?

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?

Two prisoners Jack and Jill are locked in a cell.
There is open window approx 40 feet above the ground of the cell.
They are never able to reach there.

Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Jill comes with the different plan and they escaped.

what was the plan ?

Count the Triangle in the figure given below:

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

As we know that white starts the game of chess. Can you find the scenario shown in the picture below is possible when all the white pieces are at the original place while the black pawn is not as in the below picture?

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

Can you replace the question mark with the correct number?