<h3>Physicist mixes 60 liters of 20 % solution is mixed with 20 liters of 60 % to get solution 80 liters of 30% acid solution</h3>
<em><u>Solution:</u></em>
Let "x" be the liters of 20 % solution
Then, (80 - x) is the liters of 60 % solution
Final mixture is 80 liters of 30 % solution
Therefore,
"x" liters of 20 % solution and 80 - x liters of 60 % solution is mixed to get 80 liters of 30 % solution
Thus a equation is framed as:

Thus, 60 liters of 20 % solution
Then, (80 - x) = 80 - 60 = 20
20 liters of 60 % solution