Count the Triangle in the figure given below:

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

What is full of holes but still holds water?

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?

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

If in a code language, DISTANCE is written as IDTUBECN and DOCUMENT is written as ODDVNTNE, the how will THURSDAY be coded as in the same language?

Find the last number in the series below:

voN luJ yaM raM ---

Which is faster, Heat or Cold ? Explain.

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?