What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

Using eight eights and addition only, can you make 1000?

There are three houses in a straight row. One is red, one is blue, and one is white. The red house is left of the middle. The blue house is right of the middle. Where's the white house?

You can see three almost identical images below. Can you spot the odd one out from them?

You have to put a letter on the following to make it a meaningful word. The only challenge is that you can't use 'E'.

S E Q U E N C _

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

When 99 is considered higher than 100?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?