Final answer:
The Mali rulers had a triple income due to their control of trade routes and taxation, vast agricultural lands, and the gold trade.
Step-by-step explanation:
The Mali rulers are considered to have triple income due to several factors:
- Control of trade routes and taxation: The Mali rulers controlled the trade routes and taxed merchants, earning income from importing and selling goods, including luxury items and enslaved people.
- Agricultural lands and taxes: They also had vast agricultural lands and collected taxes on them. Different areas of the empire specialized in different crops, ensuring a stable food supply and additional income.
- Gold trade: Mali was rich in gold, and the rulers earned income from the gold trade. They allowed certain gold-producing areas to remain quasi-independent vassal states to ensure a steady supply of gold.