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

Why is the Hole below a Lock?

When 99 is considered higher than 100?

What number divided by 4 is the same as that number minus 4?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

An apple seller is hosting a competition. He offers 1000 apples and 10 boxes to the people who pass by. The challenge is to put those 1000 apples in the 10 boxes in such a manner that if he asks for any amount of apples, the person can directly give him the boxes or a combination of boxes. If the person can do it, he promises to give a thousand apples for free.

If you happen to pass by the apple seller, will you be able to win a thousand apples?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?