Debra listens only to either Frank Zappa or Weird Al Yankovic. She currently buys 20 Zappa and 30 Yankovic downloads per week. She would forgo Yankovic downloads for one Zappa download at the rate of 2-1 whenever she has more Yankovic tunes that Zappas, but only 1 when the opposite is true. If you offered her 30 Zappas next week, how many Yankovic downloads would she need to remain at the same level of satisfaction? Please show work.