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

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

What came first, the chicken or the egg?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

Open a Laptop which is password protected. Hint for the password is given as below:

1 mobile 3 books 2 Boards 1 night 4 balls 2 lighters 1 ghost 1 hat 3 watches

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211