franklin's population is growing by 1000 people per year(5% of 20000 is 1000) and Chester is growing by 500 per year so at year 13 franklin will be at 32000 while Chester is at 31500
Is this a question on your test or something? I know trying out every number and letter would be difficult. There is a way to solve these types of problems. Ask your math teacher, or someone that knows this or has taught this.