"Old MacDonald had a farm." But on his farm, he only raised pigs and chickens - 48 of them all together. One day, he noticed that the total number of heads and wings was equal to the total number of feet. How many pigs and how many chickens did Old MacDonald have on his farm?

Respuesta :

chickens have  2 wings and 2 feet and 1 head
pigs have 0 wings and 4 feet and 1 head

c+p=48

c+p+2c=2c+4p
3c+p=2c+4p
minus 2c+p both sides
c=3p
subsitute 3p for c in other equation

c+p=48
3p+p=48
4p=48
divide 4
p=12
sub back

c=3p
c=3(12)
c=36


12 pigs
36 chickens