Jack and Luke were wrapping presents. Jack was able to wrap presents at a constant rate of 3 presents every 15 min. Luke was able to wrap presents at a constant rate of 5 presents every 20 min. Each boy had 20 presents to wrap, and the boys started wrapping presents at the same time.

Write an equation to find the rate each boy wraps presents. You may use y=kx or w=rt (4 points 2 for each)