Respuesta :
The correct answer is:
$54.75.
Explanation:
We only receive the discount if the majority of our usage occurs between 7 pm to 9 am. However, in the month of March we used 450 KWH between these hours and 465 KWH between 9 am to 7 pm; this means we lose our discount.
The rate per KWH is $0.05432; this means we pay
450(0.05432) = 24.444 for the hours of 7 pm to 9 am.
We also pay $0.05432/kwh for the hours of 9 am to 7 pm, but we have an additional 20% premium for the usage between these hours; this means we pay
465(0.05432)(1.2) = 30.31056, for a total of
24.444+30.31056 = 54.75456 ≈ 54.75