Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Where do fish keep their money?