1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Kipish [7]
3 years ago
13

Find the sum of the geometric series 1 + 0.8 + 0.8^2 +0.8^3 + ... + 0.8^{19}

Mathematics
1 answer:
Ainat [17]3 years ago
5 0

Answer:

S20 ≈ 4.942

Step-by-step explanation:

Sum of a geometric series is expressed as Sn = a(1-rⁿ)/1-r if r<1

a is the first term

r is the common ratio

n is the number of terms

Given the geometric series

1 + 0.8 + 0.8^2 +0.8^3 + ... + 0.8^{19}

Given a = 1,

r = 0.8/1 = 0.8²/0.8 = 0.8

n = 20 (The total number of terms in the series is 20)

Substituting this values in the formula above.

S20 = 1(1-0.8^20)/1-0.8

S20 = 1-0.01153/0.2

S20 = 0.9885/0.2

S20 ≈ 4.942

You might be interested in
What did I do wrong. I thought it was 15
CaHeK987 [17]
Its not 15 isnt it 10
3 0
3 years ago
Read 2 more answers
Plzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz help
Effectus [21]

Answer:

x=30

Step-by-step explanation:

because 3 times 30 equal 90 minus 5 is 85

7 0
3 years ago
Carla had 8 sticks of gum. She gave 2/8 of her gum to her friends. How many sticks of gum does Carla have left?
svetlana [45]


she has 6 gums left 8-2=6

8 0
3 years ago
Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used.
serg [7]

Answer:

Step-by-step explanation:

7 0
2 years ago
An average of 145 people visited a 4-day exhibition on the first 3 days. Another 205 people visited the exhibition on the fourth
Alenkinab [10]

Answer:

160 visitors.

Step-by-step explanation:

Given:

An average of 145 people visited a 4-day exhibition on the first 3 days, <u>means here average people visited in 3 days is given 145.</u>

Average = 145

Number of people, n = 3

Another 205 people visited the exhibition on the fourth day.

To find:

What is the average number of visitors per day ?

Solution:

<u>First of all we will find total number of people visited in 3 days:-</u>

As we know:

Average=\frac{Sum\ of\ observation}{number\ of\ observation}

145=\frac{Sum\ of\ observation}{3}\\

Multiplying both sides by 3

145\times3=\frac{Sum\ of\ observation}{3}\times3\\435=Sum\ of\ observations

Thus, we found that total number of people visited in 3 days is 435 and as 205 people visited in fourth day, then total number of people increased to

435 + 205 = 640

Now, sum of total observations( total number of people ) = 640

And number of observation ( number of days ) = 4

Now, we will calculate average number of visitors visit per day :-

Average=\frac{Sum\ of\ observation}{number\ of\ observation}

             =\frac{640}{4} \\=160\ visitors

Thus, the average number of visitors per day is 160 visitors.

             

6 0
3 years ago
Other questions:
  • You need to find the distance across a river, so you make a triangle. BC is 661 feet, m∠B=103.2° and m∠C=14.4°. Find AB.
    8·1 answer
  • PLEASE HELP!!!! How do I show the work to find the area of this composite figure. The answer is 81.8km I just don’t know how to
    9·1 answer
  • Solve for x<br> <img src="https://tex.z-dn.net/?f=%20%5Cfrac%7Bx%7D%7Ba%7D%20" id="TexFormula1" title=" \frac{x}{a} " alt=" \fra
    8·1 answer
  • I need help on number 8
    8·2 answers
  • Pls help forgot to do this
    10·1 answer
  • PLZ SOLVE <br><br> {5+(10+11)/7}x6
    10·1 answer
  • The local linear approximation of a function f will always be greater than or equal to the function's value if, for all x in an
    7·2 answers
  • A running track has two straight sides with length 140 m and two semicircle ends with radius 70 m. It takes Kat 40 seconds to jo
    14·1 answer
  • 2. A bank charges a $10 fee to open an account. Which of the following equations best represents the total amount in the account
    12·2 answers
  • WILL MARK BRAINLIEST IF CORRECT!!!
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!