Calculating 13% of 4500
= 0.13*4500
= $585
The refund she can expect = 585 - 495 = $90 (answer)
A. first one is your answer.
In complex calculations like this, the precedence goes like this
B = Brackets
O = Of (or Exponent)
D = Division
M = Multiplication
A = Addition
S = Substraction
So, in your formula, it will go like this
1/2x3+1/4x2
= 0.5 x 3 + 0.25 x 2
= 1.5 + 0.5
= 2
Hope this helps.
<h3>There are 189 bacteria in 5 hours</h3><h3>There are 13382588 bacteria in 1 day</h3><h3>There are

bacteria in 1 week</h3>
<em><u>Solution:</u></em>
Given that,
A type of bacteria has a very high exponential growth rate of 80% every hour
There are 10 bacteria
<em><u>The increasing function is given as:</u></em>

Where,
y is future value
a is initial value
r is growth rate
t is time period
From given,
a = 10

<em><u>Determine how many will be in 5 hours</u></em>
Substitute t = 5

y = 189
Thus, there are 189 bacteria in 5 hours
<em><u>Determine how many will be in 1 day ?</u></em>
1 day = 24 hours
Substitute t = 24

Thus, there are 13382588 bacteria in 1 day
<em><u>Determine how many will be in 1 week</u></em>
1 week = 168
Substitute t = 168

Thus there are
bacteria in 1 week