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

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

anonymous · Answer

What is the charge for using 25 therms in one month? Show your work.

anonymous · Answer

@q12157

anonymous · Answer

What is the charge for using 45 therms in one month? Show your work.

anonymous · Answer

well the first 25 therms is $0.6686/therm

anonymous · Answer

So the first 25 therms costs $(0.6686*25) in total.

anonymous · Answer

since you are buying 45 therms, there are 20 (as 45-25=20) therms that arent covered by the initial price

anonymous · Answer

so the next 20 therms cost $0.85870/therm

anonymous · Answer

The total cost of these therms is $(20*0.8587)

anonymous · Answer

SO the total cost of all 45 therms is...

anonymous · Answer

$(0.6686*25)+$(20*0.8587)

anonymous · Answer

which is equal to?

anonymous · Answer

I think you can calculate the rest :p if you need help just ask

anonymous · Answer

25 therms cost $16.715
45 therms cost $33.889

you should check my answers x3

anonymous · Answer

i got this for the 25 therms 8.8 + 25*0.6686 = 
16.715+8.8 = 25.52

anonymous · Answer

Oh yeah you need to add the monthly service charge... good job

anonymous · Answer

just add 8.8 to my answers :P

anonymous · Answer

25 therms cost $16.715+8.8=?
45 therms cost $33.889+8.8=?