A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

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

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

A man has eighty-one cows ( numbered 1,2,3...81 as such). The beauty is that cow no. 1 gives 1ltr of milk, cow no. 2 gives 2ltrs of milk and so on. The man wants to equally distribute the cows among his nine sons so that each one of them gets the same quantity of milk.

What 5-letter word typed in all capital letters can be read the same upside down?

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?

What is full of holes but still holds water?

Which is the correct shadow of the bird?