math

posted by .

in an ap the difference is between the 8th and 4th term is 20 and the 8th term is one and the half times the fourth term what is the common difference

  • math -

    since T8 = T4+4d, d=5

    and, just for completeness,

    a+7d = 3/2 (a+3d)
    a+35 = 3/2 (a+15)
    2a+70 = 3a+45
    a=25

    So, the sequence is

    25 30 35 40 45 50 55 60 ...

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Maths

    1) In the arithmetic progression, the 8th term is twice the 4th term and the 20th term is 40. Find the common difference and the sum of the terms from the 8th to the 20th term inclusive. 2) Find the least number of terms of the AP, …
  2. Arithmetic Progression

    In an AP the 6th term is half the 4th term and the 3rd term is 15. a. Find the fist term and the common difference. b. How many times are needed to give a sum that is less than 65?
  3. Math

    The nth term of an A.P. Is 3 times the 5th term.(a)find the relationship between a and d.(b)prove that the 8th term is 5times the 4th term.
  4. Maths

    The 4th term of an AP is 6 if d sum of d 8th and 9th term is -72 the common difference is
  5. math

    if 4th term of an arithmetic progression is 3 times the 1st term nd 7th term exceeds twice the third term by 1. find the first term and common difference
  6. kumasi polytechnic

    In A.P the difference between the 8th term and 4th term is 20,and the 8th term is one and half times the 4th term.Find the common difference, and the first term.
  7. Mathematics

    The 8th term of a linear sequence is 18th and 12th term is 26.find the first term and the common difference and 2th term
  8. ahisco

    In an A.P the difference between the 8th term and 4th term is 20 and the 8th term is 1half timesthe fourth term. what is the common difference and the first term of the sequence
  9. Mathematics

    If the 8th term of an AP is 36 and the 16th term is 68. Find: a) the first term b) the common difference c) The 20th term
  10. FURTHER MATHS

    The 8th term of a linear sequence is 18 and 12th term is 26.find the first term,common difference and 20th term

More Similar Questions