# Precalculus
**URL:** https://discourse.rpgclassics.com/t/precalculus/4493
**Category:** RPGC Main Forum
**Created:** [October 15, 2003, 6:39pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493 "2003-10-15T18:39:38Z")
**Posts on this page:** 11
**Page:** 2
### Author:  [@Cless\_Alvein](https://discourse.rpgclassics.com/u/Cless_Alvein)
#### Post date: [October 18, 2003, 4:03pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/21 "2003-10-18T16:03:01Z")
Consider your question:
-Daniel drives 15000 miles per year.
-The car he wants to buy is 20 mi/gallon
-Gasoline is $1.20/gallon
The question in the end asks how much mi/gallons the new car needs to save him 200 dollars. Now, I don’t know if you’ve mistyped the question or what, but you already gave me the answer when you said that the new car he wants to buy goes for 20mi/gallon. Do you mean the old car he has right now goes for 20mi/gallon?
---
### Author:  [@Mastermune](https://discourse.rpgclassics.com/u/Mastermune)
#### Post date: [October 18, 2003, 4:13pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/22 "2003-10-18T16:13:15Z")
I did not mistyped anything in the excercise and i dont know how the others in the calass did it snce i did not go to school the last two days,all i remember them saying to me the first thing you do is 15,000/200 gives 900 and that is about what i remember.But i will get back to you when they tell me what the hell did they do it ok.
---
### Author:  [@Cless\_Alvein](https://discourse.rpgclassics.com/u/Cless_Alvein)
#### Post date: [October 18, 2003, 4:27pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/23 "2003-10-18T16:27:43Z")
15000/20 \* 1.2 is how much the car has to spend on gas $900 (and according to your question, the new car).
Now there seems to be only two possibilities:
1. You typoed. You meant to type that the old car gets 20 mi / gallon, so the old car actually spends $900 on gas per year, and that you \don’t know\ the new car’s gas costs. In that case it would work like this:
15000/x \* 1.2 = 700
18000/x = 700
18000 = 700x
x = 25.71 mi/gallon (approx). This would be the \new car\'s minimum mi/gallon ratio.
1. This seems less likely, but Daniel really doesn’t know his old car’s miles/gallon, and he’s going to measure it and see if it’s worth it to buy a new car. In this case:
15000/x \* 1.2 = 1100
18000/x = 1100
18000 = 1100x
x = 16.36 mi/gallon (approx). This would be the \old car\'s maximum mi/gallon ratio.
So, which one is it? Solution #1 infers that you made a typo, and solution #2 is a very awkward and unlikely question.
---
### Author:  [@Mastermune](https://discourse.rpgclassics.com/u/Mastermune)
#### Post date: [October 18, 2003, 4:36pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/24 "2003-10-18T16:36:20Z")
I will tell you as soon as i find out which might be on monday when i get the answer ok
---
### Author:  [@Sinistral](https://discourse.rpgclassics.com/u/Sinistral)
#### Post date: [October 19, 2003, 4:12pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/25 "2003-10-19T16:12:11Z")
Nm what I wrote. Write out the questions verbatim, I’ll see if I can solve them. If my answers match cless’ , which they should, then you should be fine.
---
### Author:  [@Mastermune](https://discourse.rpgclassics.com/u/Mastermune)
#### Post date: [October 20, 2003, 1:21pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/26 "2003-10-20T13:21:46Z")
Answer #1 it is but done in a diferent way(I checked and checked but i did’nt typoed)
(15,000/x=700/1.20)1.20(x)
18,000=700x
18,000/700=700x/700
x=25.7miles per galon
---
### Author:  [@Cless\_Alvein](https://discourse.rpgclassics.com/u/Cless_Alvein)
#### Post date: [October 20, 2003, 2:59pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/27 "2003-10-20T14:59:59Z")
Uh, then yes, you did typo, if 25.7 is the answer.
> 2-Darnell drives about 15,000miles each year.he is planning to buy a new car.\The car he wants to buy averages 20 miles on one gallon of gasoline.\He has decided he would buy another car if he could save at least $200 a year in gasoline expenses.Assume gasoline costs $1.20 per gallon.What is the minimum number of miles per gallon that would fulfill Darnell’s criteria?
You meant to say that the car he has average 20 miles on one gallon.
---
### Author:  [@Mastermune](https://discourse.rpgclassics.com/u/Mastermune)
#### Post date: [October 20, 2003, 3:07pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/28 "2003-10-20T15:07:39Z")
But i did not i got the book right in my hands this moments and that is how it says it,maybe it was the books mistake since the one i have tends to have some mistakes
---
### Author:  [@Heaven\_s\_Soldier](https://discourse.rpgclassics.com/u/Heaven_s_Soldier)
#### Post date: [October 21, 2003, 9:36am UTC](https://discourse.rpgclassics.com/t/precalculus/4493/29 "2003-10-21T09:36:35Z")
If the book was finished quickly then it will have mistakes. The one I have is full of them, just because they needed it out in time.
---
### Author:  [@Videospirit](https://discourse.rpgclassics.com/u/Videospirit)
#### Post date: [October 21, 2003, 10:06am UTC](https://discourse.rpgclassics.com/t/precalculus/4493/30 "2003-10-21T10:06:21Z")
Are you sure the book doesn’t want you to round your answers up? that would get you the answer of 8.
---
### Author:  [@BahamutXero](https://discourse.rpgclassics.com/u/BahamutXero)
#### Post date: [October 21, 2003, 12:44pm UTC](https://discourse.rpgclassics.com/t/precalculus/4493/31 "2003-10-21T12:44:51Z")
I’ve taken college Business Calculus but as of now all I’m good for is basic algebra. I guess I know where I’m coming if I need help. Great job Cless.
[Previous page](https://discourse.rpgclassics.com/t/precalculus/4493.md?page=1)