Results 1 to 3 of 3

Thread: Arithmetic Progression

  1. #1

    Thread Starter
    New Member
    Join Date
    Mar 2012
    Posts
    2

    Arithmetic Progression

    I was going through my chapter i have a question as Find sum of first 22 terms of an AP in which d =7 and 22nd term is 149

    d = 7

    a22 = 149

    n=22 s22 = ?

    an = a + (n - 1 ) d

    149 = a + ( 22 - 1) 7

    149 = a + 147

    a = 2

    From where we can say that an = 149 for reference my chapter book is http://www.youtube.com/watch?v=j3AcMEc2t-A

  2. #2
    Only Slightly Obsessive jemidiah's Avatar
    Join Date
    Apr 2002
    Posts
    2,431

    Re: Arithmetic Progression

    You don't know how we went from
    an = a + (n - 1 ) d
    to
    149 = a + ( 22 - 1) 7?

    an is the nth term of the arithmetic progression, by definition. We're given that the 22nd term is 149, so a22 = 149--this is just an assumption we're given. In going from the first line to the second line we just substitute all of the information we know--that d=7, and that in the case n=22 we have an = a22 = 149. Is that clear? I have difficulty understanding your difficulty so I also have trouble explaining it away.
    The time you enjoy wasting is not wasted time.
    Bertrand Russell

    <- Remember to rate posts you find helpful.

  3. #3

    Thread Starter
    New Member
    Join Date
    Mar 2012
    Posts
    2

    Re: Arithmetic Progression

    Thanks jemidiah for clarifying me the problem. I hope i can get one more clarification from you. I have a maths problem in my chapter Find HCF of two numbers 135 and 225 by Euclid's division algorithm. http://www.youtube.com/watch?v=9CqtrMyhBPY . I was not well so i couldn't attend school when my master was teaching Euclid's division algorithm. So without knowing what is Euclid's division algorithm how could i solve HCF of two numbers 135 and 225 by Euclid's division algorithm.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Click Here to Expand Forum to Full Width