Charlene is knitting a baby blanket. She wants its width, w, to be at least half its length, l. She estimates that she has enough yarn to put fringe around the blanket, as long as the perimeter of the blanket is no more than 180 inches. The system of inequalities shown represents the width of the blanket in inches, w, and the length in inches, l.

w ≥ 0.5l

2l + 2w ≤ 180

What is the maximum length possible for her blanket?

30 inches
45 inches
60 inches
90 inches