8. Donald, Ryan, and Zaki went to Northern on Main Café. Zaki purchased four sandwiches, a cup of coffee,
and ten doughnuts for $1.69. Ryan purchased three sandwiches, a cup of coffee and seven doughnuts for $1.26.
Assuming all sandwiches sell for the same unit price, all cups of coffee sell for the same unit price, and all
doughnuts sell for the same unit price, what did Donald pay for a sandwich, a cup of coffee, and a doughnut?