Question

Students at Williams Elementary hold an annual carwash. Soap for their carwash is purchased at a cost of $5.95 per gallon plus a shipping cost of $10. Which table shows the relationship of the total cost of soap and the amount of gallons purchased?

A. gallons of soap | Total cost (dollars)
12 | 191.40
16 | 255.20
20 | 319
24 | 398.75

B: gallons of soap | Total cost (dollars)
12 | 71.40
16 | 95.20
20 | 119
24 | 142.80

C: gallons of soap | Total cost (dollars)
12 | 120
16 | 160
20| 200
24 | 240

D. gallons of soap | Total cost (dollars)
12 | 81.40
16 | 105.20
20 | 129
24 | 152.80

Answer 1

To determine the correct table that represents the relationship between the total cost of soap and the amount of gallons purchased, we can use the given costs.

The total cost can be calculated using the formula:
\[
\text{Total Cost} = \text{Cost per Gallon} \times \text{Gallons} + \text{Shipping Cost}
\]
where:
- Cost per Gallon = $5.95
- Shipping Cost = $10

Let's calculate the total cost for different amounts of gallons:

1. For 12 gallons:
\[
\text{Total Cost} = (5.95 \times 12) + 10 = 71.40 + 10 = 81.40
\]

2. For 16 gallons:
\[
\text{Total Cost} = (5.95 \times 16) + 10 = 95.20 + 10 = 105.20
\]

3. For 20 gallons:
\[
\text{Total Cost} = (5.95 \times 20) + 10 = 119.00 + 10 = 129.00
\]

4. For 24 gallons:
\[
\text{Total Cost} = (5.95 \times 24) + 10 = 142.80 + 10 = 152.80
\]

Now we can compare these calculated costs with the options given:

**A:**
- 12 -> 191.40 (incorrect)
- 16 -> 255.20 (incorrect)
- 20 -> 319 (incorrect)
- 24 -> 398.75 (incorrect)

**B:**
- 12 -> 71.40 (incorrect)
- 16 -> 95.20 (incorrect)
- 20 -> 119 (incorrect)
- 24 -> 142.80 (incorrect)

**C:**
- 12 -> 120 (incorrect)
- 16 -> 160 (incorrect)
- 20 -> 200 (incorrect)
- 24 -> 240 (incorrect)

**D:**
- 12 -> **81.40** (correct)
- 16 -> **105.20** (correct)
- 20 -> **129** (correct)
- 24 -> **152.80** (correct)

So, the correct table is **D**.