A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

just_one_last_goodbye

  • one year ago

10 owl bucks if you help me

  • This Question is Closed
  1. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Cory has 15 die-cast cars in his collection. Each year his collection increases by 20%. Roger has 40 cars in his collection. Each year he collects 1 additional car. Part A: Write functions to represent Cory and Roger's collections throughout the years. (4 points) Part B: How many cars does Cory have after 6 years? How many does Roger have after the same number of years? (2 points) Part C: After approximately how many years is the number of cars that Cory and Roger have the same? Justify your answer mathematically. (4 points)

  2. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Hi again!

  3. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So for part A, Roger's function is relatively easy to figure out

  4. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Ok ^_^ i closed my question cause i know u'll help me

  5. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So since he is constantly adding one more and he already starts with 40, we know it will be y=x+40 Where 40 is the constant (he starts with this many) x is the rate at which he adds cars (he adds one so its 1x, but thats the same as x)

  6. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    thats part A?

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    not all, we need cory's too

  8. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    hold on, I'm just gonna figure this out, cory's is a bit weird

  9. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    can u give me direct answers? :/ sorry im going to get screamed at and probably get punished physically if i dont get it done

  10. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    double check the question, because cory's is a bit weird

  11. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorta hard to explain whats weird

  12. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Cory has 15 die-cast cars in his collection. Each year his collection increases by 20%. Roger has 40 cars in his collection. Each year he collects 1 additional car. Part A: Write functions to represent Cory and Roger's collections throughout the years. (4 points) Part B: How many cars does Cory have after 6 years? How many does Roger have after the same number of years? (2 points) Part C: After approximately how many years is the number of cars that Cory and Roger have the same? Justify your answer mathematically. (4 points)

  13. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    im copying and pasting it

  14. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorry nix, thats wrong

  15. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    because think about it, if x is zero, then the whole thing would be zero. But he starts out with 15 cars so it has to be something else

  16. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    Cory: \(y = 15(1.2)^x\)

  17. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The question is weird because his collection increases by 20% every year. So its increasing by 20% then increase 20% of that 20%. Essentialy its something like (15x1.2)1.2 etc.

  18. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    YES thats genius

  19. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    mathstudent is right

  20. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so A is for cory, y=15(1.2)^x and for roger, y=x+40

  21. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    For B, just plug in 6 for x

  22. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    for both equations. So for roger it would be 46, and for cory 44.78976

  23. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but then we can't have a bit of a car.... so i guess 44?

  24. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    wait which is part a?

  25. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    cory, y=15(1.2)^x and for roger, y=x+40

  26. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its asking for the functions in A

  27. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    ahh so those are the functions correct?

  28. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yea

  29. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    and for C

  30. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    part b?

  31. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    For B just plug in x

  32. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i mean 6 for x

  33. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so I put "plug in x"

  34. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 3

    Here is the explanation of Cory's function. He starts with 15 cars. His cars go up by 20% at the end of each year. After 1 year, he has \(1.2 \times 15\) At the begining of the second year, he starts with \(1.2 \times 15\) cars. At the end of year 2, he now has \(1.2 \times (1.2 \times 15) = 15 \times (1.2)^2\) At the end of year 3, he has \(1.2 \times (1.2 \times(1.2 \times 15)) = 15 \times 1.2^3\) That pattern leads to the equation: After x years, he has y cars \(y = 15(1.2)^x\)

  35. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    NONONONON0

  36. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    oh so put "6 for x" in part b?

  37. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    For B you plug in 6 for x yourself, and thats the answers

  38. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    we definitely know rogers, which is 46 y=6+40

  39. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    y = 15(1.2)^x

  40. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    44.78976

  41. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    But, idk what your instructor wants, because you can't have like 2/3 of a car

  42. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    idk im just gonna submit only part a

  43. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    thanks anyways please medal @mathstudent55

  44. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No problem, sorry could be that big of a help

  45. just_one_last_goodbye
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    it's alright

  46. nonopro
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    let's name "x" the number of years. we know that 15 +15*1.20^{x} =40+x let's try after 5 years: Roger would have 45 cars and Cory 52 ( i just guessed 5, and then I calculated 15 +15*1.20^{5} ): so, no, it has to be less than 5. let's try 4: Roger will have 44, and cory 15+31=45, so that's quite good asnwer! Let's try with 3: Roger will have 43, and Cory 15+ 25=40, so 4 years are better: after approximately 4 years. (perhaps a better strategy would be to just calculate after each year starting at 1 and going up...)

  47. nonopro
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    message me back if i got it right

  48. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.