There are 12 heads and 40 feet in the same cage. How many chickens and rabbits are there in the cage?

There are 12 heads and 40 feet in the same cage. How many chickens and rabbits are there in the cage?

There are: (40-12 × 2) △ 4-2, = 16 △ 2, = 8 (rabbits); there are: 12-8 = 4 (chickens); a: there are 4 chickens and 8 rabbits