A store is selling two mixtures of nuts in 20-ounce bags. The first mixture has 13
ounces of peanuts combined with five ounces of cashews, and costs $6.00. The
second mixture has five ounces of peanuts and 15 ounces of cashews, and costs
$8.00. How much does one ounce of peanuts and one ounce of cashews cost?