# 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

## 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