To solve this problem you must apply the proccedure shown below:
1. You must make a system of equation by using the information given in the problem above. Then, let's call:
: The number of computers sold.
: The number of hard drives sold.
2. Therefore, you have the following system of equations:

2. Solve for
in the first equation and substitute it into the second equation:

3. Solve for
:

4. Substitute the value of
into the first equation to calculate
:

Therefore, the answer is: The store sold
computers and
hard drives.
The population will reach 540 000 in 30.8 yr.
The formula for population growth is
<em>P</em>_<em>t</em> = <em>P</em>_0 × e^(<em>rt</em>)
540 000 = 270 000 × e^(0.0225t)
e^(0.0225t) = 2
0.0225t = ln2
t = (ln2)/0.0225 = 30.8
Square root of 70 is about 8
Square root of 144 is 12
Square root of 188 is about 13