What is the word or phrase?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

I can write cow in 13 letters.

Can You?

Can you count the number of lines in the below picture?

The centre of the third figure is empty. What digit should fit inside?

Replace the (?) with the correct mathematical signs to make the expression equal to 59.

18 ? 12 ? 4 ? 5 = 59

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

There is a unique number which when multiplied by any number from 1 to 6, we will get the new number that contains the same digits only.

Can you find that number?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

A guy in his thirties is found dead in a forest. The shocking thing about the body is that he is wearing his swimming trunks snorkel and a facemask.

For your information, the nearest lake is some 10 miles away and the sea is hundreds of miles away.

How did he die then?