web2.0calc
 
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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?
Round your final answer to the nearest integer. 

 

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

8+0 Answers

 #1
avatar+128475 
+3

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

 

cool cool cool

 Jan 2, 2020
 #2
avatar+17 
+1

So you use the formula?

 Jan 2, 2020
 #3
avatar+17 
+1

But it doesn't have a common-

oh is it 10?

JiminBang  Jan 2, 2020
 #5
avatar+17 
+1

1.10

JiminBang  Jan 2, 2020
 #6
avatar+17 
0

1.10 because 100+10 but since its percent, 1.10

JiminBang  Jan 2, 2020
 #4
avatar+17 
+1

Got it

 

 

Thank you CPhill!

 Jan 2, 2020
edited by JiminBang  Jan 2, 2020
 #7
avatar+128475 
0

OK....welcome  !!!

 

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

 

cool cool cool

CPhill  Jan 2, 2020
 #8
avatar+17 
+1

Got it double thx!

JiminBang  Jan 2, 2020

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