Using four sevens (7) and a one (1) create the number 100. Except for the five numerals, you can use the usual mathematical operations (+, -, x, :), root and brackets ()

Can you write down eight eights so that they add up to one thousand?

Can it be possible to build a house that has all its four walls facing towards the South?

In a family supper, a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one daughter-in-law, and one mother-in-law need to sit at a table.

There are only seven chairs available at the place. How many more chairs do they have to borrow so that everyone can sit down together for the suppers if everybody requires a separate chair?

How many triangles can you find in this given picture?

Can you fill the blank with the correct number?

6 30 870 756030 _____

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Solve the following series:
AZ, GT, MN, __, YB

I can write cow in 13 letters.

Can You?