Answer:
20 rabbits, 10 chickens
Explanation:
Because chickens and rabbits each have 2 eyes, the number of animals is 60 ÷ 2 = 30.
Let's say that all of the 30 animals are chickens. There would be a total of 30 × 2 = 60 legs.
So the extra (100 – 60) = 40 legs must have come from the rabbits.
Every rabbit has (4 – 2) = 2 more legs than a chicken.
So there are 40 ÷ 2 = 20 rabbits and 30 – 20 = 10 chickens.