A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing


  • one year ago

the sum of the first fifteen terms of an arithmetical progression is 105 and the sum of the next fifteen terms is 780. find the first three terms of the arithmetical prgoression.

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

    in an arithmetic progression there are two parameters, those are a = the starting value d= the difference between two concecutive values so from that you can derive any value on the series by \(a_n = a + (n-1)d\) Since you know about these series im sure you also know how to take the sum of n conecutive points in a series using that twice youll be able to get two equations since there are ony two unknowns (a and d) using those two equations find the values for those two parameters. Use above equation to find the first three values on the series

  2. 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...


  • 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.