To determine the cost per room for Spot on Cleaning, we divide the total cost by the number of rooms:
\[ \text{Cost per room for Spot on Cleaning} = \frac{300 \text{ dollars}}{6 \text{ rooms}} = 50 \text{ dollars per room} \]
Carpet Cleaning Pros charges $40 per room.
Comparing the two costs:
- Carpet Cleaning Pros: $40 per room
- Spot on Cleaning: $50 per room
The less-expensive company is Carpet Cleaning Pros, with a cost of $40 per room.