Lisa's barn has 20 animals that have 62 legs in total. She only has cows and geese. How many cows and how many geese does she have?

9 geese

11 cows

Step-by-step explanation:

Say x is cows, and y is geese.

x + y = 20 animals

x * 4 + y * 2 = 62

x = 20 - y

(20 - y) * 4 + y * 2 = 62

80 - 4y + 2y = 62

- 2y = - 18

y = 9 geese

x = 20 - 9 = 11 cows