What happened when the wheel was invented?

What is the largest number you can write with just 3 digits?

Can you move 2 matchsticks to form four equal sized squares.

I am the fastest animal but cannot climb the tree. What am I?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

I know a nine-letter word having only one vowel.
Do you ?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

What is red and smells like blue paint?