How do you solve this equation?

One-third of the people from country a claim that they are from country b, and the rest admit they are from country a. one-fourth of the people from country claim that they are from country a, and the rest admit they are from country b. in a combined census of the two countries, one-half of the total claimed to be from a. what is the ratio of the populations of country a to that of country b.

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

What is the range of the relation in the table below? x y –2 0 –1 2 0 4 1 2 2 0