What is the area of a rectangular holding pond with length 8/15 mile and width 1/6 mile?

as you already know, the area of a rectangle is just length*width, so is just the product of those two.

if you are saying purchasing 3 social media ads and one newspaper ad counts as one purchase then there are:

6 purchases

if you are asking how many of each then:

18 social media ads

6 newspaper ads