The problem of chickens and rabbits in the same cage in primary school mathematics education edition

1, chickens and rabbits live in the same cage. * * * There are 30 heads and 78 feet. How many chickens and rabbits are there?

Solution 1: Treat all 30 rabbits,

(30*4-78)/2

=( 120-78)/2

=42/2

=2 1 (only)

30-2 1=9 (only)

Answer: 2 chickens1and 9 rabbits.

Solution 2: Treat all 30 rabbits,

(78-30*2)/2

=(78-60)/2

= 18/2

=9 (only)

30-9=2 1 (only)

2. The chicken and the rabbit are in the same cage. * * * has 20 heads and 56 feet. How many chickens and rabbits are there?

Chicken: (20*4-56)/2

=(80-56)/2

=24/2

= 12 (only)

Rabbit: 20- 12=8 (only)

3, chickens and rabbits in the same cage, * * * has a head 43, feet 132, how many chickens and rabbits are there?

Chicken: (43*4- 132)/2

=( 172- 132)/2

=40/2

=20 (only)

Rabbit: 43-20=23 (only)