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avatar+4116 

Please help asap!! 

suppose that the amount of algae in a pond doubles every 4 hours.if the pond initially contains 90 pounds of algae ,how much algae will be in the pond after 12 hours? 

the answer choices is: 
A) 720 pounds 
B)  360 pounds 
C)  1,440 pounds 
D) 114 pounds

 May 23, 2018
 #1
avatar
+3

Its A

 May 23, 2018
 #2
avatar+128055 
+2

We have this:

 

A  = 90 * (2)^(t/4)       where A is the amount present after  t hours

 

So...after 12 hours, we have

 

 

A  = 90 * (2) ^(12/4)

 

A = 90  *  (2)^3

 

A = 90 * 8

 

A =  720 pounds  =  "A"

 

 

cool cool cool

 May 23, 2018
 #4
avatar+4609 
+2

We have 90*2*2*2, because it doubles every 4 hours, and 12/4=3, so 3 two's.

Thus, the answer is \(\boxed{720}\)

smileysmiley

 May 23, 2018

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