Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

marv_1

  • one year ago

A lumberjack has 4n + 110 logs in a pile consisting of n layers. Each layer has two more logs than the layer directly above it. If the top layer has six logs, how many layers are there? Write the steps to calculate the equation for the problem and state the number of layers.

  • This Question is Closed
  1. jessica.17
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So for the topmost layer you have 6 logs, then you have 8, then 10 etc. 6 + (6+2) + (6+2+2)+...+(6+2(n-1)) = 4n + 110. You have to find the sum of an arithmetic sequence with first term 6 and common difference 2 with n terms. First term: 6, Last term: 2n+4. Then substitute Sum of sequence = 4n+110 and solve for n.

  2. marv_1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay this would be 4 divided by 110?

  3. marv_1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    =25n

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

    Sorry, what is 25n? Sum of sequence or?

  5. marv_1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    no the answer

  6. marv_1
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I'm really not sure how to do this

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

    Okay, so how would you find the sum of an arithmetic series? Say, if I told you the first term was 6, the last was 14, and the common difference was 2. (6 + 8 + 10 + 12 + 14.) Apart from adding them up one by one.

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

    Since the terms increased by the same amount each time, you could take the average and multiply it by the number of terms. The average would be (first term + last term)/2.

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

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.