An experiment that involves learning in animals requires placing white mice and rabbits into separate, controlled environments, environment I and environment II. The maximum amount of time available in environment I is 200 minutes, and the maximum amount of time available in environment II is 100 minutes. The white mice must spend 16 minutes in environment I and 20 minutes in environment II, and the rabbits must spend 15 minutes in environment I and 50 minutes in environment II. Write a system of inequalities that describes the constraints on the number of each type of animal used in the experiment. Let x denote the number of white mice and y denote the number of rabbits.