arithmetic

The 9th term of an A.p is 32 while the12th termis70.find the sum of it 20th term

  1. 👍 0
  2. 👎 0
  3. 👁 172
  1. "The 9th term of an A.p is 32" ---> a + 8d = 32
    "the12th termis70" ----> a + 11d = 70

    subract them: 3d = 38
    d = 38/3

    then in first : a + 304/3 = 32
    a = -208/3

    term(20) = a + 19d = -208/3 + 19(38/3) = 514/3

    You said " find the sum of it 20th term"
    That makes no sense.
    Do you want the 20th term, which I found for you
    or
    Do you want the sum of the first 20 terms.

    I will let you do the arithmetic for you ...

    sum(20) = 10[ 2(-208/3) + 19(38/3) ]
    = ....

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. math

    The 9th term of an AP is 8 and the 4th term is 20. Find the first term and the common difference.

    asked by lindsay on April 6, 2013
  2. MATHS

    The 9th and 22nd term of the AP are aw and 55 respectively. find the sum of the 70 term

    asked by PATIENCE JOHNBEE on November 1, 2016
  3. Math

    An Ap is given by K,2k/3,K/3,0.....Find the 6th term, Find the nth term. If the 20th term is equal to 15 find K

    asked by Munyua on September 30, 2016
  4. Further math

    The sum of the 3rd and 7th term of an AP is 38 and the 9th term is 37. Find the AP.

    asked by Joshua on February 24, 2019
  5. arithmetic

    THE SUM OF THE 2ND AND 5TH TERMS OF AN A.P IS 42. IF THE DIFFERENCE BETWEEN THE 6TH AND 3RD TERM IS 12, FIND THE: COMMON DIFFERENCE, 1ST TERM, 20TH TERM.

    asked by JOSHUA BAME on November 26, 2010
  1. maths

    the first term of arithmetic progression is -8 .and the ratio of the 7th and the 9th term is 5 :8 .find the common difference.

    asked by mafo on October 20, 2014
  2. Math PLEASE HELP PLEASE PLEASE PLEASE

    Question 1 Write the first four terms of the sequence whose general term is given. an = 3n - 1 Answer 2, 3, 4, 5 2, 5, 8, 11 -2, -5, -8, -11 4, 7, 10, 13 3 points Question 2 Write the first four terms of the sequence whose general

    asked by Tony on July 10, 2012
  3. math

    the 9th term of an AP is 52 while the 12th term is 70.find the sum of its 20th term

    asked by Anonymous on October 14, 2011
  4. mathematics

    the sixth term of an AP is 35 and 13th term is 77.find the 20th term.

    asked by Anonymous on March 5, 2019
  5. Math

    The sum of the 3rd and 7th terms of an a.p is 36, and the 9th term is 37. Find the a.p

    asked by Chidiebere on March 17, 2018
  6. Cht Ningi

    The 9th And 22nd Term Of An A.P Are 29 And 55 Respectively. Find The Sum Of It's First 60 Terms

    asked by Elijah on December 6, 2015

You can view more similar questions or ask a new question.