A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

During which month do people sleep the least?

Can you find out the total number of triangles in the given figure?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

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?

What is the next number in the series?

15 29 56 108 208 ?

Spot what is wrong here in below Picture?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

How old is your son? asked a man to his neighbour. My son is five times as old as my daughter and my wife is five times as old as my son. I am twice as old as my wife whereas my grandmother, who is celebrating her eighty-first birthday is as old as all of us put together.

How old is the man's son ?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?