#5.
First you divide 200 miles by 5, then multiply that number by 7.
Why?
You have to find out how many miles one inch represents to know how many miles 7 inches is.
#6.
Divide 48 by 6, then multiply that number by 3.
Why?
For every 6 yards of material, 3 yards of trim is used to make one costume. So when you divide 48 by 6, you find out how many yards of material us needed to make ___ costumes. Multiplying ___ by 3 will show how many yards of trim she needs.
I hope this helped. Im really bad at finding rules sorry.