I am having issues with understanding the steps for the following problem. I do not want the answer, but it would be extremely helpful if I could get assistance with understanding the steps.

Problem: Gabriella has just started a new job with a $51,000 salary at a company with a 401(k) plan that has a 75% match up to 3% of her gross salary.She figures she can afford to save $1,000/yr for her retirement.Based on our ""plan of action for investing"" for retirement, how many dollars of her annual savings should Gabriella contribute to her Roth IRA each year?

My question is, how do I figure out how many dollars of her annual savings should she contribute to her Roth IRA each year? What are steps to finding the answer?