There is a box in which distinct numbered balls have been kept. You have to pick two balls randomly from the lot.

If someone is offering you a 2 to 1 odds that the numbers will be relatively prime, for example
If the balls you picked had the numbers 6 and 13, you lose $1.
If the balls you picked had the numbers 5 and 25, you win $2.

Will you accept that bet?

Can you name some countries which do not have the alphabet 'A' in them?

Why is a river so rich ?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Count the number of squares in the picture below.

Queen Elizabeth organised a royal party.

To Avoid uninvited guest royal family set a password.
Jack (an uninvited person) plan to enter the party. He stand nearby the door.

First guest comes, the security person said 'twelve' and guest replied with six.
Second guest comes , the security person said 'six' and guest replied with 'three'.

Jack thought is enough and he walked to the entry point. The security person said 'eight' , Jack replied smilingly 'four'.
He was immediately thrown out of the party. why ?

Can you write down eight eights so that they add up to one thousand?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?