Question

Help please?
Find the sum of the following infinite geometric series, if it exists.
4 + 3 + 2.25 + 1.6875 +…



Does not exist


12


14


16

Answer 1

well, the formula for the sum of an infinite geometric series is a/(1-r), where a is the first term and r is the common ratio

you can find the common ratio by dividing the second number by the first number; in this case, we get r = 3/4

an important thing to note is that this formula will only work if r < 1, which works because 3/4 < 1

Answer 2

so the answers 16?

Answer 3

yup!

Answer 4

Thank you!