It takes Lacey 3 hours to knit a stocking cap and 5 hours to knit a pair of mittens. She has at most 20 hours of spare time in a week and knits at least one pair of mittens each week. Let x stand for the number of stocking caps and let y stand for the number of pairs of mittens. Write a system of linear inequalities that models the number of stocking caps and pairs of mittens that Lacey can knit in a week. Graph the solution.