Alexis can wash a total of 14 windows in 1 hour
<h3><u>Solution:</u></h3>
Given that Alexis washes 
windows in 
hours
<u><em>To find: </em></u>number of windows washed in one hour
To simplify the calculations we will convert the given mixed fraction to improper fraction
Hence, to wash 10.5 windows, Alexis takes 0.75 hours
Let "n" be the number of windows washed in 1 hour
10.5 windows ⇒ 0.75 hours
"n" windows ⇒ 1 hour
By cross-multiplication we get,
Thus Alexis can wash 14 windows in one hour
Step-by-step explanation:
Answer:
i think it would be B bc its not A or C
Step-by-step explanation:
Surface area of box=1200 cm²
<span>Volume of box=s²h </span>
<span>s = side of square base </span>
<span>h = height of box </span>
<span>S.A. = s² + 4sh </span>
<span>S.A. = surface area or 1200 cm², s²
= the square base, and 4sh = the four 'walls' of the box. </span>
<span>1200 = s² + 4sh </span>
<span>1200 - s² = 4sh </span>
<span>(1200 - s²)/(4s) = h </span>
<span>v(s) = s²((1200 - s²)/(4s)) </span>
<span>v(s) = s(1200 - s²)/4 . </span>
<span>v(s) = 300s - (1/4)s^3</span>
by derivating
<span>v'(s) = 300 - (3/4)s² </span>
<span>0 = 300 - (3/4)s² </span>
<span>-300 = (-3/4)s² </span>
<span>400 = s² </span>
<span>s = -20 and 20. </span>
again derivating
<span>v"(s) = -(3/2)s </span>
<span>v"(-20) = -(3/2)(-20) </span>
<span>v"(-20) = 30 </span>
<span>v"(20) = -(3/2)(20) </span>
<span>v"(20) = -30 </span>
<span>v(s) = 300s - (1/4)s^3 </span>
<span>v(s) = 300(20) - (1/4)(20)^3 </span>
<span>v(s) = 6000 - (1/4)(8000) </span>
<span>v = 6000 - 2000
v=4000</span>
The population ten years ago was 6,000.
Because the population doubled you divide 12,000 by 2
12,000 / 2 = 6,000
