Math

Calculate the sum of the infinite series 72 + 60 + 50 + 125/3 + ...

489
432
360
307

Can someone please help me with this one? I can never solve these on my own:(

  1. 1
asked by Max
  1. if it is geometric, r=60/72=10/12=5/6
    adn then 5/6(60=50
    and then 40(5/6)=200/6=100/3, so that is not a geometric series. Did your teacher make an error? Lets test if she meant it to be a geometric series, r=5/6

    sum=72/(1-5/6)=72*6=amazing, the answer is there.

    So I bet your teacher meant 100/3 as the fourth term.

    posted by bobpursley
  2. Oh ok, thank you so much.

    posted by Max
  3. Nah. Where did you get the 40? 50 * 5/6 = 250/6 = 125/3

    so, you have a genuine GP, with
    a = 72
    r = 5/6

    So, S = 72/(1 - 5/6) = 72*6 = 432

    posted by Steve

Respond to this Question

First Name

Your Response

Similar Questions

  1. Pre-Calculus

    Q.Determine the sum of each infinite geometric series. t_1= 8 r = -2^1/2 ---------------------------------------- A.This is a divergent series because the absolute value of r is greater than 1.
  2. Algebra 2

    Describe an infinite geometric series with a beginning value of 2 that converges to 10. What are the first four terms of the sequence? a{1} = first term of series                ∞    Infinite
  3. Math

    Does the following infinite geometric series diverge or converge? Explain. 1/5 + 1/25 + 1/125 + 1/625 A) It diverges; it has a sum. B) It converges; it has a sum. C) It diverges; it does not have a sum. D) It converges; it does
  4. algebra

    Okay, I was taught that if a geometric series is infinite and it diverges then it has no limit and no sum. Looking back in my notes, I found an example of finding the value for a divergent series? Is this possible? The sum of an
  5. math

    Find the sum of the infinite geometric series, if possible. 12 + 10 + 25/3 + 125/18 + ...
  6. algebra

    Can someone please help me with this problem? Thanks! Evaluate the infinite geometric series: 8+4+2+1+... I thought you needed to know the number of terms to evaluate, but how do you know them if it is infinite? The limit of Sn =
  7. Algebra 2

    I need steps on how to complete this please i am so confused and lost. :( Consider the infinite geometric series x e n=1 -4(1/3) n-1. In this image, the lower limit of the summation notation is "n=1". a. Write the first four terms
  8. math

    determine the difference between the sum of the infinite geometric series 18-6+2-2/3...and the sum of the first 6 terms of the series (round to 3 decimal places) first i did S=18/ (1+1/3)= 13 1/2 Sn= 18(1+(1/3)^6) _____________ 1
  9. Calculus

    Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(
  10. calculus

    Consider the infinite series of the form: (+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)... (A) Find x and y from: x(

More Similar Questions