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

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

Name a key which is hardest to turn.

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

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

There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.

How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Can you find the six hidden animals in the picture below?

What does this rebus picture identify?