To determine how many acres will be harvested in 10 hours, we first need to find the rate of the combine machine in acres per hour.
The combine can harvest 189 acres in 6 hours. We can calculate the harvesting rate as follows:
\[ \text{Rate} = \frac{\text{Total Acres}}{\text{Total Hours}} = \frac{189 \text{ acres}}{6 \text{ hours}} = 31.5 \text{ acres per hour} \]
Next, we can find out how many acres will be harvested in 10 hours by multiplying the harvesting rate by the number of hours:
\[ \text{Acres harvested in 10 hours} = \text{Rate} \times \text{Number of hours} = 31.5 \text{ acres per hour} \times 10 \text{ hours} = 315 \text{ acres} \]
Therefore, the combine will harvest 315 acres in 10 hours.