Due to the drought in California, many communities now have tiered water rates. There are different rates for Conservation Usage, Normal Usage, and Excessive Usage. The usage is measured in the number of hundred cubic feet (hcf) that the property owner uses. During the summer, a property owner will pay $24.72 plus $1.32 per hcf for Conservation Usage. The bill for Conservation Usage would be between or equal to $31.32 and $52.12. How many hcf can the owner use if she wants her usage to stay in the conservation range?

Enter truncated values for answers. Example: Enter 8.93 as 8 and 6.34 as 6.