Can you place six X (crosses) in below board without making three in a row in any way ?

There are hundred red gems and hundred blue gems. The blue gems are priceless while the red gems equal wastage. You have two sacks one labeled Heads and the other Tails. You have to distribute the gems as you want in the two sacks. Then a coin will be flipped and you will be asked to pick up a gem randomly from the corresponding sacks.

How will you distribute the gems between the sacks so that the odds of picking a Blue gem are maximum?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

Can you find out the remainder when 3^300 is divided by 5?

What does this Rebus Picture mean?

If eleven plus two equals one, what does nine plus five equal?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

If we tell you that there is a relation between the numbers and letters in the given figure, can you analyze it and find the missing letter in the last box?