Farmer Jones raises ducks and cows. He looks out his window and sees 54 animals with a total of 122 feet. If each animal is "normal", have many of each type of animal does he have

47 ducks and 7 cows

Step-by-step explanation:

Ducks have 2 legs and cows have 4 legs.

If all the animals are ducks,

number of legs = 54 (2) = 108

Difference in number of legs = 122 - 108 = 14

Difference in no. of legs per animal = 4 - 2 = 2

Number of cows=14 : 2 = 7

Number of ducks = 54-7 = 47

Thus, he have 47 ducks and 7 cows.

Let's check:

Total number of feet = 7 (4) + 47 (2) = 122 ✓

You could also first assume that all the animals are cows. The answer would be the same.