Isaiah uses 1,275 kWh of electricity
= 400 kWh + 875kWh
Standard use plan:
7.5 cents/kWh for the first 400 kWh
10 cents/kWh for anything over 400 kWh
With standard use plan, Isaiah would pay:
7.5 * 400 cents + 10 * 875 cents
= 3,000 cents + 8,750 cents
= 11,750 cents
= $117.50
Isaiah uses 1,275 kWh of electricity
On-peak usage = 575 kWh
Off-peak usage = 1,275kWh – 575kWh = 700kWh
Interval use plan:
On-peak hours - 15 cents/kWh
Off-peak hours - 3 cents/kWh
With Interval use plan, Isaiah would pay:
15 * 575 cents + 3 * 700 cents
= 8,625 cents + 2,100 cents
= 10,725 cents
= $107.25
Answer: Option A
Standard use plan - $117.50
Interval use plan - $107.25