What is always in front of you but can’t be seen?

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?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

What does this simple rebus mean?

The more it dries, the wetter it becomes. Can you tell what it is?

You can hear me, but you can't touch or see me.

What am I?

A bomb exploded in a room full of married couples and no one died. How?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?