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

What Adam and Eve do not have but the rest of the people have?

Identify the 10 differences between the two given pictures.

Two Twins Jack and Jill were standing back to back and suddenly they started running in opposite direction for 4 kilometres and then turn to left and run for another 3 kilometres.

what is the distance between the Baggio twins when they stop ?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

You are given 16 witch hats. The hats are divided in four different colours – red, blue, green and yellow. Every colour has been assigned to four hats. Now each of the hat will be glued with a label of an arithmetic sign – ‘+’, ‘-‘, ‘x’ or ‘/’. But you can label one sign only once on one colour. In such an arrangement, the hats can be uniquely defined by its colour and symbol.

Can you arrange all the 16 hats in a 4x4 grid in a fashion that no two rows and columns have a repetition of colour or sign?
We have arranged four hats in the below picture to assist you.

Can you find out which number multiplied by itself will give the output as 12345678987654321?

What has 88 keys?