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

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

A train full of passengers goes through a tunnel. When the train comes out from the other end, there is no single person on the train.

How did it happen?

What Does this text mean:

important=important

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

What do you think with the below Picture ?

What is the Surname of Barbie Doll?

How many triangles are there in the picture below?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Find the Odd One Out?
84129
32418
47632
36119
67626
72927