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

How many triangles are there in the picture below?

Make a sentence consisting of three words that have the whole alphabet.

A boy was locked in a room by some robbers. All that is in the room is a piano, a calendar, and a bed. The room is locked from the outside. What does he eat, drink, and how does he escape and get out?

What is the difference between a jeweller and a jailer?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?

I always drive my customer away.

Who am I?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Find the hidden panda in the image below.

A convention is held where all the big logicians are summoned. The master places a band on everyone's forehead. Now all of them can see others bands but can't see his own. Then they are told that there are different colours of bands. All the logicians sit in circle and they are further explained that a bell will ring at regular intervals. The moment when a logician knew the colour of band on his forehead, he will leave at the next bell. If anyone leaves at the wrong bell, he will be disqualified.

The master assures the logicians that the puzzle will not be impossible for anyone of them. How will the logicians manage ?