What is the sum of the first five terms of a geometric series with a1 = 20 and r = 1/4?

1 answer:

4 0

Sum of the first n terms of a geometric sequence is Sn = a(1 - r^n)/(1 - r)
Sn = 20(1 - (1/4)^5)/(1 - 1/4) = 20(1 - 1/1024)/(3/4) = 20(1023/1024)/(3/4) = 26 41/64

You might be interested in

Write the name of the period that has the digits 486

kogti [31]

1. <span>The name of period that has 486 in the given number which is 751 486 is hundreds.
period is considered to a group of places of the digits, like the given number 486 is the group of hundred because the highest number it contains is 400.
=> 400 + 80 + 6
=> 4 hundreds + 8 tens + 6 ones
=> 486
while 751 is the period of hundred thousands.
=> 700 000 + 50 000 + 1 000
=> 751 000

</span>

8 0

3 years ago

How do you solve what is 30% of $240

DerKrebs [107]

The Answer would be x=72. Why? Because $\frac{x}{240} = \frac{30}{100}. Fraction \frac{30}{100}$ is your %. You Cross multiply 240 * 30 = 100x
240 time 30 = 7200. you want x to be alone so you do 7200 divided by 100 equaling 72. So you get x=72.

6 0

3 years ago

Finding out how many events can someone attend with the cost of $36

Tcecarenko [31]

They're allowed to join for $15. And for every event, they have to pay $3.

3x = 21

x = 7

Someone who has $36 can attend 7 events.

6 0

3 years ago

-4 = - 17 + x linear equations

Llana [10]

add 17 to both sides

13 = x

<em>hope this helps</em>