If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

What is next number in the pattern below:

131 517 192 123 ?

What's a single-digit number with no value?

Replace the question mark with the correct number in below Picture:

Solve the mathematical equation in the picture below.

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

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.