I don't know the root you are talking about but i would say "we might say that they are bulk"
$900
Explanation
First, you would need to find the area of the carpet which would be length x width, equaling to 400 ft., then you’d multiply the area of the carpet (400ft) by the cost for each square foot (2.25) leaving you with the total, $900
We have that
if the <span>machine can bottle 30 fluid ounces of shampoo in -----------> 12 seconds
X f</span>luid ounces of shampoo in-----------------------------------------------> 1 second
X=30/12=2.5 (<span>I apply a rule of three)
</span>
the answer is 2.5 fluid ounces of shampoo