In a big farm in Wisconsin, there are only hens and cows. When the owner counted the heads of the stock in the farm, the number summed up to $200$, while counting the number of legs, the number summed up to $540$. How many more hens were there in the farm ? Assume each cow had $4$ legs and each hen had $2$ legs.
Option C. 60
Let number of hens = H
and number of cows = C
1H + 1C = 200 ….(1)
and 2H + 4C = 540 ….(2)
by solving the above equations, H = 130 and C = 70
Number of more hens = 130 – 70 = 60.