19539 bacteria will be present after 18 hours
<u>Solution:</u>
Initial value of bacteria N = 6000
Value after 4 hours 
= 7800
<em><u>The standard exponential equation is given as:</u></em>
where
N is amount after time t
No is the initial amount
k is the constant rate of growth
t is time
Plugging in the values in formula we get,
Solving for "k" we get,
Taking "ln" on both sides, we get
On solving for ln, we get k = -0.0656
The equation becomes, 
Now put "t" = 18,
Hence the bacteria present after 18 hours is 19539
Answer:
17.22 mpg................................
Answer:
X=8
Step-by-step explanation:
24×10=30X
240=30X
Divide by 30
X=8
Answer:
Option A is correct, i.e. 3 mph.
Step-by-step explanation:
Tinh can row at a rate of 6 mph in still water.
Suppose the speed of the river current is X mph.
Then Upstream speed = (6-X) mph.
And Downstream speed = (6+X) mph.
It takes her 2 hours to row upstream from a dock to a park. She then rows back to the dock, and it only takes 40 minutes.
It means Distance upstream = Distance downstream.
Speed upstream x Time upstream = Speed downstream x Time downstream.
(6-x) * 2 = (6+x) * 40/60
12 - 2x = 4 + 2x/3
12 - 4 = 2x/3 + 2x
8 = 2x/3 + 6x/3 = 8x/3
x = 3 mph.
Hence, option A is correct, i.e. 3 mph.
C. is the correct answer because (x+3)^2 is x^2+6x+9
