Final answer:
The rulers of Moscow worked with the Mongols to maintain their power and protection and to benefit economically through trade and travel.
Step-by-step explanation:
The rulers of Moscow worked with the Mongols for several reasons. Firstly, the Mongols were a powerful military force that had conquered much of the region, including Kiev, the main city in Russia at the time.
By aligning themselves with the Mongols, the rulers of Moscow were able to maintain their own power and protect their city from potential attacks. Additionally, working with the Mongols provided economic benefits, as the Mongols established a postal-station system that allowed for trade and travel, benefiting merchants in the region.