Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

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

O T T F F S S ?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

In a guessing game, five friends had to guess the exact numbers of apples in a covered basket.
Friends guessed 22, 24, 29, 33, and 38, but none of the guesses was correct. The guesses were off by 1, 8, 6, 3, and 8 (in random order).

Can you determine the number of apples in a basket from this information?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

This was asked in an interview with Coa-Cola.

The interviewer has given me 100 marbles(50 white and 50 black) and two empty boxes.
He then told me that he will leave the room and i need to place all the marbles in two boxes.

And When he come back, he will draw a marble from any of the two box and if the marble is white I will be hired.

Also
* No box can be empty.
* All 100 marbles must be placed in one of the two boxes.

So what should I have done?

Forwards I am heavy, backward I am not. What am I?

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

What number when divided in half becomes zero?