CAN SOMEONE HELP ME :)​

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.

Q1 which of the following is a factor of a)37 b)53 c)62 d)82 q2) if the sum of 2016 different whole numbers is odd. at most how many of the numbers can be even a)0 b)1 c)2014 d)2015

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?