Question

Sarah lives in a part of the country where there are droughts. consequently the water company increases the cost per ccf of water based on usage. the piecewise function shows the rate of the schedule.

{ 0.18(x) when X is less than or equal to 160
c(x) { 0.18(160) + 0.22(x-160) when 160 is less than X less than or equal to 240
{0.18(160) + 0.22(x-160) + 0.24(x-240) when X is greater than 240

If sarah used 210 ccf of water last month, what was she charged ?

A: 37.80 B : 38.80 C : 39.80 D : 47.00 Show your work

Answer 1

hey there!

the answer is :B : 38.80

hope it helps!

Answer 2

Option C is correct that is She was charged by 39.80.

Explanation:

Given Functions are

when x ≤ 160 , c(x) = 0.18(x)

when 160 < x ≤ 240 , then c(x) = 0.18(160) + 0.22(x-160)

when x >240 , then c(x) = 0.18(160) + 0.22(x-160) + 0.24(x-240)

We are also given that Sarah used 210 ccf of water that means x = 210 which is greater than 160 and less than 240. So we chose 2nd function of c(x)

⇒ c(x) = 0.18(160) + 0.22(x-160)

⇒ c(210) = 0.18(160) + 0.22(210-160) = 28.8 + 0.22 × 50 = 28.8 + 11 = 39.8

Therefore, Option C is correct that is She was charged by 39.80.