Let 
be the number of liters of the 10% solution to be used, and 
the number of liters of the 4% solution. The chemist wants to end up with a 4 liter solution, so
For each liter used in the mixture, a concentration of either 10% or 4% acid will be contributed, and the goal is to make a 4L solution whose concentration is 7%, which means
Solving for 
gives 
, so 2L of both solutions is needed.
Use the formula a^2 + b^2 = c^2
so you’re set up would be 4^2 + 12 1/3^2 = c^2
Answer:
control
Step-by-step explanation:
Answer:
n=4
Step-by-step explanation:
-28 divided by -7 is 4
<span>Population density is divided in to three forms that are physiological density, arithmetic density and agricultural density.
The number of people per unit area is the physiological density, it is also known as the real population density and total number of people divided by the total land area is arithmetic density population.
And if we compare both for India, The physiological density of India is greater than the arithmetic population density.</span>
