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# Ana started off her penny collection with 1 penny. She then adds 5 pennies to her penny collection each day.

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Ana started off her penny collection with 1 penny. She then adds 5 pennies to her penny collection each day.

how could you change the above scenario to make it a geometric series rather than an arithmetic series?

Using the answer, how many pennies would ana have in total after 10 days?

show and use the formula to calculate

show all work

pls help i struggle.. thank you

Apr 30, 2019

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May 2, 2019
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Ok, when there is a geometric sequence, each TERM is multiplied by the common ratio to get the NEXT TERM.

So you can make the common ratio 5, for example.

Geometric sequence: She starts with 1 penny, and adds five times her current amount to her penny collection every day.

How many pennies she would have after 10 days?

Formula for sum of finite geometric sequence $$S_n=\frac{a(r^n-1)}{r-1}$$

Plugging in what we know -

n = 10 (term)

r = 5 (common ratio)

a = 1 (first term)

9765624/4 = 2441406 pennies.

May 4, 2019