In the Virginia Plan, the number of legislators in each house would be determined by what?

The population of free inhabitants.

Explanation:

The Virginia Plan suggested first and foremost that the United States govern by way of a bicameral legislature. This system would split legislators into two houses, as opposed to the single assembly put forth by the New Jersey Plan, and legislators would be held to specified term limits.

According to the Virginia Plan, each state would be represented by a number of legislators determined by the population of free inhabitants. Such a proposal was of benefit to Virginia and other large states, but smaller states with lower populations were concerned that they wouldn't have enough representation.