Question

The Westview Health Club is installing low-flow showerheads to conserve water. The owners are deciding between two types of showerhead. The KL-50 showerhead uses 7.5 gallons of water for a 5-minute shower. This table shows how much water the HR-2.0 showerhead uses:
HR-2.0 water usage
Time (minutes) Water (gallons)
3 5.4
7 12.6
8 14.4
Which showerhead uses less water per minute?
How much water would that showerhead use for a 6-minute shower?

Answer 1

To determine which showerhead uses less water per minute, we need to calculate the water usage rate (in gallons per minute) for both the KL-50 and HR-2.0 showerheads.

### KL-50 Showerhead
- Water used: 7.5 gallons
- Shower time: 5 minutes

Water usage rate for KL-50:
\[
\text{Rate} = \frac{\text{Water used}}{\text{Time}} = \frac{7.5 \text{ gallons}}{5 \text{ minutes}} = 1.5 \text{ gallons per minute}
\]

### HR-2.0 Showerhead
Now, we need to calculate the water usage rate for the HR-2.0 showerhead based on the data provided:

1. For 3 minutes:
\[
\text{Rate} = \frac{5.4 \text{ gallons}}{3 \text{ minutes}} = 1.8 \text{ gallons per minute}
\]

2. For 7 minutes:
\[
\text{Rate} = \frac{12.6 \text{ gallons}}{7 \text{ minutes}} = 1.8 \text{ gallons per minute}
\]

3. For 8 minutes:
\[
\text{Rate} = \frac{14.4 \text{ gallons}}{8 \text{ minutes}} = 1.8 \text{ gallons per minute}
\]

### Comparison
- KL-50: 1.5 gallons per minute
- HR-2.0: 1.8 gallons per minute

The KL-50 showerhead uses less water per minute.

### Water Usage for a 6-Minute Shower with the KL-50 Showerhead
To find out how much water the KL-50 showerhead would use for a 6-minute shower:
\[
\text{Water used} = \text{Rate} \times \text{Time} = 1.5 \text{ gallons per minute} \times 6 \text{ minutes} = 9 \text{ gallons}
\]

### Summary
- The KL-50 showerhead uses less water per minute (1.5 gallons/minute).
- For a 6-minute shower, the KL-50 showerhead would use 9 gallons.