Mr. Cooper has 8 1/4 ounces of a chemical solution.
He will put an equal amount of the solution into 3 test tubes. We need to find the amount of solution in each test tube. It can be done by dividing total volume and 3.
Step-by-step explanation: You do 24÷3 because he has a string that is 24 inches long and if he wanted to divide it into 3 equal pieces . You would get 8 inches long for each piece (8x3) or (3x8)