Maths Help Needed - Distance and Direction

Hi

I am stuck with a sheet I got from school and i dont understand what the question means. Ive attached a picture of the street/houses and hope one of you guys could figure out the answer to the last 2 questions

1. Find a Rule for the numbers of two houses if one house is due south of the other house

2. Find a rule for the numbers of two houses if one house is due north-west of the other house.

Any Ideas ?

Help Needed

Thanks

1. Look at pairs of houses in which one house is due south of the other house. These pairs are
(6, 7), (5, 8), (4, 9), (3, 10), (2, 11), and (1, 12)

There are a number of equivalent rules here, but one is that the sum of the house numbers is 13. Another is that the average is 6.5.


2. Again, look at pairs:
(1, 18), (2, 17), (3, 16), (4, 15), (5, 14), (6, 13)

Rules: sum is 19; average is 9.5.