There are forty elephants and they have forty-fore heads. How can this be possible?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

Can you write down eight eights so that they add up to one thousand?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

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

Take one out and scratch my head, I am now black but once was red. What am I?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

If,

20 % 5 = 24

21 % 7 = 33

42 % 6 = 67

Then;

66 % 6 = ?

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

The host of a game show, offers the guest a choice of three doors. Behind one is a 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?