What is the degree of dissociation of the electrolyte if 60 of every 200 of its molecules have decayed into ions?

Answer: a = 30%.
Explanation of the solution to the problem: to solve this problem, you need to know the definition of the degree of dissociation.
The degree of dissociation is the ratio of the dissociated molecules of a substance to the total number of its molecules, that is:
a = (n * 100%) / N, where a is the degree of dissociation of the electrolyte, expressed as a percentage; n is the number of dissociated molecules of the substance (in this case n = 60); N is the total number of molecules of the substance (N = 200).
Substituting the values known from the condition of the problem into the formula, we obtain:
a = (n * 100%) / N = (60 * 100%) / 200 = 30%.