How did commerce between egypt and nubia lead to interdependence answers?

Commerce between Egypt and Nubia led to interdependence between Egypt and Nubia because Egypt needed some things from Nubia and Nubia needed some from Egypt. Trade therefore brought them together. Egypt’s soils were rich but they didn’t have minerals, horses and other useful resources found in Nubia. Nubia on the other hand exchanged their goods for, mainly food supplies from Egypt.