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# ~I tried~

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A new shopping mall records 120 total shoppers on their first day of business.

Each day after that, the number of shoppers is 10% more than the number of shoppers the day before.

What is the total number of shoppers that visited the mall in the first 7 days?

I know I could just dumbly math it out, but is there a better way?

Could somebody give me a hint?

Thank you!!!

Jan 2, 2020

#1
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Total  number  =

120 [  1-  r^n]  / [ 1 - 1.10]    where  r  =1.10    and n  = 7

120   [  1 - 1.10^7  ] /  [ 1  -1.10]      1138  people

Jan 2, 2020
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So you use the formula?

Jan 2, 2020
#3
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But it doesn't have a common-

oh is it 10?

JiminBang  Jan 2, 2020
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1.10

JiminBang  Jan 2, 2020
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1.10 because 100+10 but since its percent, 1.10

JiminBang  Jan 2, 2020
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Got it

Thank you CPhill!

Jan 2, 2020
edited by JiminBang  Jan 2, 2020
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OK....welcome  !!!

[This is just the "formula"  for  the sum of a finite geometric series   ]

CPhill  Jan 2, 2020
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Got it double thx!

JiminBang  Jan 2, 2020