A mail carrier delivered mail to 84 houses and 3 hours at what rate did the mail carrier deliver the mail?

Ineed with number 6 , explain how to get 1978

When solving this problem: 3025/5.5 = a/90.75 you get 49912.5 which would be the length of one of the sides of a square when the area is only 90.75 inches. is that answer correct, why, and how is it possible?

What are two numbers that have a sum of 15