21 liters of the 12% solution and 4 liters of the 37% solution
Step-by-step explanation:
Represent the number of liters of the first solution as x and the second as y. Now, the total liters of iodine is going to be 16% of 25 = 4 liters of iodine, and the total liters of each solution is going to be 25. Now, we can setup two equations: