Using Only Five 5's and any mathematical operator make sum as 37

What is greater than gold but cannot be bought. it can never be sold and can earn if its sought. though it can be broken, it can still be fixed. for by birth it can't start nor by death it is ended.what am i?

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Prove that twice of ten is the same as twice of eleven.

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Why is a river so rich ?

No one wants to have it, but if one got it, he does not want to lose it. What is It?

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?