Savanna is working part time at a local snack bar. She mostly sells peanuts and cashew nuts on Mondays. Savannah sells both peanuts and cashews nuts by the pound. Peanuts are $3.00 per pound and cashew nuts are $5.00 per pound. This past Monday, she sold $81.00 worth of peanuts and cashews and a total of 21 items sold. How many pounds of peanuts were sold and how many pounds of cashews were sold?