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

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

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

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

What does this rebus puzzle means ?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?