Question

A power company calculates a person's monthly bill from the number of

kilowatt-hours (kWh), x, used.
The function b(x) = {
0.15x,
x < 200
0.10 (x - 200) + 30, 2 > 200
determines
the bill.
How much is the bill for a person who uses 700 kWh in a month?
A. $100
оо
B. $80
O C. $105
O D. $95
PREVIOUS

Answer 1

Answer: (b)

Explanation:

Given

Function for bill calculation is

`\Rightarrow b(x)=\left \{ {{0.15x\quad \quad \quad \, \ \ \ \ x<200} \atop {0.1(x-200)+30\quad x>200}} \right.`

The consumption is 700 kWh i.e. more than 200

Therefore, bill is given by the second function i.e.
`0.10(x-200)+30`

Substitute 700 for x to get the bill

`\Rightarrow 0.1(700-200)+30\\\Rightarrow 50+30=\$80`

Hence, option (b) is correct.