## anonymous one year ago Petrolyn motor oil is a combination of natural oil and synthetic oil. It contains 3 liters of natural oil for every 2 liters of synthetic oil. If 198 liters of synthetic oil are used, how many liters of Petrolyn oil will be made?

1. anonymous

I bet you are annoyed at this point of me but I just have this big packet of homework and I need help. @jim_thompson5910 If you can help thanks and if you cant its fine I understand

2. jim_thompson5910

so we'll have a proportion we need to set up first do you have a proportion? or are you stuck on that part?

3. anonymous

Im stuck on the proportion

4. anonymous

3/2=x/198?

5. jim_thompson5910

this will be the basic template $\Large \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}} = \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}}$

6. anonymous

so then it would be 2x=594?

7. jim_thompson5910

we know that " It contains 3 liters of natural oil for every 2 liters of synthetic oil" focus on one side, say the right side replace "natural oil" with 3 replace "synthetic oil" with 2 $\Large \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}} = \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}}$ $\Large \frac{3}{2} = \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}}$

8. jim_thompson5910

yeah you have the right idea, doing 2 more replacements gives $\Large \frac{3}{2} = \frac{\text{amount of natural oil}}{\text{amount of synthetic oil}}$ $\Large \frac{3}{2} = \frac{x}{198}$

9. jim_thompson5910

and yes, when you cross multiply you will get 2x = 594

10. anonymous

right yes so then x would be

11. anonymous

x=297

12. jim_thompson5910

yep

13. anonymous

Thank you again

14. jim_thompson5910

297 isn't the amount of Petrolyn oil though 297 is the amount of natural oil

15. anonymous

16. jim_thompson5910

hmm let me think

17. jim_thompson5910

oh I'm overthinking, yeah we add amount of petrolyn oil = (amount of natural oil) + (amount of synthetic oil)

18. anonymous

so its 495

19. jim_thompson5910

correct

20. anonymous

great! :)