What is black when you buy it, red when you use it, and gray when you throw it away?

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

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

Why do Chinese men eat more rice than Japanese men do ?

I make two people out of one. What am I?

A lion and its tamer are standing inside a cage that measures 1 unit in radius. Both of them can effortlessly run at the speed of 1 unit maximum.

1) Suppose the lion is hungry, will he be able to eat up the tamer?
2) If yes, how long can the tamer survive?

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I can be cracked, made, told, and played. What am I?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you write down eight eights so that they add up to one thousand?