To calculate the total cost of your energy usage with the “Limited Plan,” let’s break it down into two parts:
- Calculate the cost of usage between 7:00 p.m. and 9:00 a.m. (450 kWh) with a 15% discount.
- Calculate the cost of usage between 9:00 a.m. and 7:00 p.m. (465 kWh) with a 20% premium.
Step 1: Calculate the cost of night usage (7:00 p.m. to 9:00 a.m.)
- Normal rate = $0.05432 per kWh
- Discount = 15%
- Discounted rate = Normal rate - (Normal rate × Discount)
\[ \text{Discounted rate} = 0.05432 - (0.05432 \times 0.15) = 0.05432 - 0.008148 = 0.046172 \]
- Cost for night usage:
\[ \text{Cost (Night)} = 450 \text{ kWh} \times 0.046172 = 20.77 \]
Step 2: Calculate the cost of day usage (9:00 a.m. to 7:00 p.m.)
- Premium = 20%
- Premium rate = Normal rate + (Normal rate × Premium)
\[ \text{Premium rate} = 0.05432 + (0.05432 \times 0.20) = 0.05432 + 0.010864 = 0.065184 \]
- Cost for day usage:
\[ \text{Cost (Day)} = 465 \text{ kWh} \times 0.065184 = 30.33 \]
Step 3: Add both costs together:
\[ \text{Total cost} = \text{Cost (Night)} + \text{Cost (Day)} = 20.77 + 30.33 = 51.10 \]
Since we need to find one of the corresponding answers, rounding to suit the options given, it looks like $51.08 is the closest valid choice.
Thus, the answer is:
$51.08