Can you find out the missing number in the grid?

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

O T T F F S S ?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?

A Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?

81 x 9 = 801. What must you do to make the this equation true?

The cream is heavier than Milk. True or False?

Can you find out the total number of triangles in the given figure?

You are a thief and you are being punished for your crime. People have tied your head down on a tree with a rope that has been anchored in the ground. A candle is burning below the rope which is slowly burning it away. Just below your head, a Lion has been left loose and is waiting for you to drop down on the ground so he can have you as his lunch.

You have to survive the scenario. How will you do it?

You have four chains. Each chain has three links in it. Although it is difficult to cut the links, you wish to make a single loop with all 12 links. What is the fewest number of cuts you must make to accomplish this task?