Question

There is an animal farm where chickens and cows live. All together, there are 84 heads and 210 legs. How many chickens and cows are there on the farm?

Answer 1

1 Chicken have = 2 legs

1 Cow have = 4 legs

No of cows = x

No of chickens = y

Total no of legs = 4x + 2y = 210.............(1)

Total No of heads = x + y = 84................(2)

x = 84 - y....( from (2) )

Substituting the above equation in (1)

4 ( 84 - y) + 2y = 210

336 - 4y + 2y = 210

336 - 2y = 210

-2y = -126

= y = 63

No of cows = 84-63 = 21

∴ Total no of cows = 21

Total no of chickens = 63