Answer: produce more output in plant 1 and less in plant 2.
Step-by-step explanation:
From the question, we are given the information that a multiplant monopolist can produce her output in either of two plants and that she discovers that when marginal revenue is $50, the marginal cost in plant 1 is $70 while the marginal cost in plant 2 is $75.
Since the marginal cost in plant 2 is higher than that of plant 1, to maximize profits the firm will produce more output in plant 1 and less in plant 2.