What is so fragile that saying its name breaks it?

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

0 0 0 = 6
1 1 1 = 6
2 2 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

You can use any mathematical symbols in the space provided to make all above algebraic expressions true.

What jumps when it walks and sits when it stands?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

I am an odd number. Take away a letter and I become even. What number am I?

There’s a one-story house in which everything is yellow. Yellow walls, yellow doors, yellow furniture. What colour are the stairs?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?