Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

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?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

Who is that with a neck and no head, two arms and no hands? What is it?

A man started to town with a fox, a goose, and a sack of corn. He came to a stream which he had to cross in a tiny boat. He could only take one across at a time. He could not leave the fox alone with the goose or the goose alone with the corn. How did he get them all safely over the stream?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?