Which word does the below Plexor means ?

What jumps when it walks and sits when it stands?

Find out the number of circles in the given picture having Illusion

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

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 do you call a fish without an eye?

I have Rs.50 and I spend it in the way as below.

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?