Question

A gas company has the following rate schedule for natural gas usage in single-family residences:

Monthly service charge $8.80

Per therm service charge
1st 25 therms $0.6686/therm
Over 25 therms $0.85870/therm

What is the charge for using 25 therms in one month?
What is the charge for using 45 therms in one month?
Construct a function that gives the monthly charge C for x therms of gas.

Answer 1

ganeshia can you help please

Answer 2

monthly service charge is flat. you have to pay it no matter how many therms you use.

Answer 3

What is the charge for using 25 therms in one month?

monthly service charge + something

Answer 4

since you've used only 25 therms, they'll charge you $0.6686/therm

Answer 5

so, total charge for using 25 therms in one month = 8.8 + 25*0.6686

= ?

Answer 6

16.715+8.8 = 25.52

Answer 7

correct, next q

Answer 8

What is the charge for using 45 therms in one month?


45 = 25 + 20

so for first 25 therms they'll charge u .6686/therm, and rest of the 20 they'll charge u 0.85870/therm

Answer 9

8.8 + 25*.6686 + 20*.85870

Answer 10

25.52+17.174 = 42.694

Answer 11

thats right ! next is the tricky part

Answer 12

for this i have written this

C(x) = { 8.8 + 0.6686x if 0 ≤ x ≤ 25
{ 25.515 + 0.133219(x - 25) if x > 25

Answer 13

how did u get 0.133219 ?

Answer 14

it should be, 0.85870 right ?

Answer 15

i thought of subtracting it from 0.6686

Answer 16

i see you did most of it real good,

Answer 17

can you help me with some similar questions Please

Answer 18

C(x) = { 8.8 + 0.6686x if 0 ≤ x ≤ 25
{ 25.515 + 0.85870(x - 25) if x > 25

Answer 19

we dont have to subtract cuz, you accounted for the first 25 therms in 25.515 :

25.515 = 8.8 + 25*.6686

Answer 20

so rest of the therms, we need to multiply flat with .85870

Answer 21

sure post them il be happy to help if i can :D

Answer 22

http://prntscr.com/1504bo

Answer 23

@ganeshie8

Answer 24

v = 12 falls in 2nd ? so use it

plugin v=12, t = 15

Answer 25

http://www.wolframalpha.com/input/?i=33-%28%2810.45%2B10*sqrt%2812%29-12%29%2833-15%29%29%2F2204

Answer 26

ganiesha we have to answer it in 3 parts

Answer 27

@ganeshie8

Answer 28

where are the 3 parts

Answer 29

the function has 3 parts, but only one we can use. so solution doesnt require 3 parts