Answer:
Option (A)
Step-by-step explanation:
From the given piecewise function that represent the amount of bill from number of units of electricity used is 'x' kWh.
b(x) = 0.10x when x ≤ 200
0.15(x - 200) + 20 when x > 200
For x = 400 kWh,
Function which represents the expenses of the bill,
b(400) = 0.15(400 - 200) + 20 [Since x > 200]
= 0.15(200) + 20
= 30 + 20
= $50
Therefore, Option (A) will be the answer.
