If Rajina's daughter is my daughter's mom, who am I to Rajina?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

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

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

A man is shown a portrait painting. He looks closely, then tells, “Brothers and sisters have I none, but that man’s father is my father’s son!” Who is the man in the portrait?

Can you make a fire with just a single stick?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

A Car driver was heading down a street in Washington. He went right past a stop sign without stopping, he turned left where there was a 'no left turn' sign and he went the wrong way on a one-way street. Then he went on the right side of the road past a cop car. Still, he didn't break any traffic laws. Why not?

Buy me, smell me or deliver me, I do not change.

Who am I?