Question

A farm raises cows and chickens. The farmer has a total of 40 animals. One day he counts the legs of all his animals and realizes he has a total of 118 legs. How many cows does the farmer have?

Answer 1

Answer: the farmer has 19 cows.

Step-by-step explanation:

Let x represent the number of cows that the farmer has.

Let y represent the number of chicken that the farmer has.

The farmer has a total of 40 animals. It means that

x + y = 40

A cow has 4 legs. A chicken has 2 legs. One day he counts the legs of all his animals and realizes he has a total of 118 legs. It means that

4x + 2y = 118- - - - - - - - 1

Substituting x = 40 - y into equation 1, it becomes

4(40 - y) + 2y = 118

160 - 4y + 2y = 118

- 4y + 2y = 118 - 160

- 2y = - 42

y = - 42/ - 2

y = 21

x = 40 - y = 40 - 21

x = 19